• There are various errors in windows platform they are:

• • Processor overheating
  • Bad RAM
  • Hard disk issues
  • File system issues and display options

• Recently Chipmakers have been working to make processors more effective, which means they generate less heat.
• Now some modern processors still produce a lot of heat.

• • Dust is preventing the fan from spinning smoothly.
  • The fan motor has failed.
  • The fan bearings are loose and jiggling.

• Several conditions can lead to RAM-related performance problems with a particular machine:

• • RAM timing is slower than optimal machine spec.
  • RAM has minor faults that appear only on detailed testing.
  • RAM is overheating.

• Slow access times on the affected drive.
• An increasing number of bad sectors when running scandisk.
• Unexplained Blue Screens.
• Intermittent boot failures.
• An “Imminent Hard Disk Failure” warning.

• Some file systems work better than others for large disk dividers. Windows 7 should always use the NTFS file system for best performance.
• Cleaning up the file system will also help speed performance. We can use the Disk Clean-up tool to:

• • Remove temporary Internet files.
  • Remove downloaded program files (such as Microsoft ActiveX controls and Java applets).
  • Remove the Recycle Bin.
  • Remove Windows temporary files such as error reports.
  • Remove optional Windows components we don’t use.
  • Remove installed programs you no longer use.
  • Remove unused restore points and shadow copies from System Restore

• To run Disk Clean-up in Windows 7, click Start and type “Disk Clean-up” in the search box. Select the drive you want to clean up.

• Windows have corrupted in many problems we have use below steps, to overcome this issues.

• It will start Windows by using a minimum set of drivers and start up programs.
• It will also eliminate software conflicts that could occur when you install a program, or an update , or when you run a program in Windows.

• These are services that Windows Update needs to make sure it’s working effectively.

• Using Command Prompt running as Administrator, we can perform these commands that can fix issues on our system itself,

• The System is recognized as a complete system “Fruit Bazaar System. The main actors for this system as Admin, Users, ShippingAgent.

• User can Log-in, add, remove items to cart, register, pay.
• Admin can have privileged login, they can change, modify catalog, to maintain the user data. In cart adding items then they can make an order. Un order database orders are stored.
• The orders are processed and items from the warehouse are delivered to customer by shipping agent.

• CartCustomer/User can browse the catalog and can add items to their cart for ordering. Moreover, Customer can remove items from their cart and after adding items to their cart they can checkout and move to Ordering.
• For Order a customer should to be log-in.
• Registration Maintenance
• Admin can maintain the Catalog. The Catalog contains all items they are in stock with their rates.
• Dynamic rates according to market value can also change the catalog information by Admin. He can add and remove the items from catalog and stocks.

• User can manage their profile. Profile handling includes changing their account information like email, shipping address, passwords.
• If the user has created an invalid account then Admin can be removing the account or can intimate User about any fault in their profile.
• Physical Transaction At the time of delivery A shipping Agent which will take the items from warehouse along with the bill and deliver the item to customer.
• Customer will pay the respective bill and the bill id will be stored in transaction database.
• Cash transaction should be keeping record like in transaction database which will store bill amount and bill id.
• LOGINUser enter their login-id along with password. If the entered data is valid combination then homepage will be displayed.
• Otherwise a message intimating user about them invalidate login details.
• After placing Order Customer will be intimated by an order confirmation mail and sending a SMS containing order details and delivery time.

• Create two new value sets for the parameters that are to be used.
• Query the concurrent program definition.
• Go into Parameters window.
• Attach the value set to each of the parameters that are being used.

• The concurrent programe is nothing but instances of execution file along with parameter and incompatible programs.
• We can register 11 types of executable as Concurrent Programe.

• We can execute multi language programs as Concurrent Programe.
• When we run Concurrent Programe we can utilize 100% local machine hardware capacity.
• We can change the Concurrent Programe output based on employee profile.
• We can submit only Request.
• We can schedule the Concurrent Programe as per client requirement.

• Joins are SELECT commands that retrieve data from two or more tables.
• The WHERE clause usually gives the join conditions that determine how data is selected from each table in the join to fill in the specified columns in the select list.
• Joins are used to return rows.
• Join is an integral part of the select statement.

• Subquery is a SELECT statement within another SQL Statement.
• Subqueries structure a complex query into isolated parts.
• Subqueries allow you to use the results of another query in the outer query.

• • The currently running process may be interrupted and moved to the ready state by the OS.
  • The resources (mainly CPU cycles) are allocated to the process for the limited amount of time and then is taken away, and the process is again placed back in the ready queue if that process still has CPU burst time remaining.

• • That process stays in ready queue till it gets next chance to execute.
  • The decision to preempt may be performed when,
    • A new process arrives (with a higher priority than the current process)

Preemptive Scheduling

• • An interrupt occurs (fairness)
  • Periodically based on clock interrupt. (Eg: Round Robin)

• More robust, one process cannot monopolize the CPU.
• Fairness. The OS makes sure that CPU usage is the same by all running process.

• Context switch cost: Time taken by the scheduler to suspend the running task, switch the context, and dispatch the new incoming task.

• Memory management is the process of controlling and coordinating computer memory, assigning portions called blocks to various running programs to optimize overall system performance.
• Memory management resides in hardware, in the OS (operating system), and in applications.
• In hardware, memory management involves components that physically store data, such as RAM chips, memory caches,etc.,.
• In the OS, memory management involves the allocation (and constant reallocation) of specific memory blocks to individual programs as user demands change.
• At the application level, memory management ensures the availability of adequate memory for the objects and data structures of each running program at all times.Application memory management combines two related tasks, known as allocation and recycling.
  • Allocation : When the program requests a block of memory, a part of the memory manager called the allocator assigns that block to the program.
  • Recycling : When a program no longer needs the data in previously allocated memory blocks, those blocks become available for reassignment. This task can be done manually (by the programmer) or automatically (by the memory manager).

• As processes are loaded and removed from memory, the free memory space has broken into small pieces.
• That processes cannot be allocated to memory blocks considering their small size and memory blocks remains unused.
• This problem is known as Fragmentation.There are two types of fragmentation,
  • Internal fragmentation
  • External fragmentation

• Memory block assigned to process is lager. Memory is left unused in some portion as it cannot be used by another process.

• Total memory space is enough to satisfy a request or to reside a process in it, but it is not contiguous, so it cannot be used.

• A thread is a flow of execution through the process code, with its own program counter that keeps way of which instruction to execute next, system registers which hold its existing working variables, and a stack which contains the execution history. A thread is also called as lightweight process.
• A thread shares with its peer threads few information like code segment, data segment and open files.
• To improve application performance through parallelism.
• Threads represent a software approach to improving performance of operating system by reducing the overhead thread is equivalent to a classical process.
• Each thread has exactly one process and no thread can exist outside a process. Each thread signifies a separate flow of control.
• Implementing network servers and web server.
• They are also offer a suitable foundation for parallel execution of applications on shared memory multiprocessors.
• The working process of a single-threaded and a multithreaded are shows in the following figure.

• The context switching time minimize in thread concepts.
• Use of threads offers concurrency within a process.
• Efficient communication.
• It is more economical to create and context switch threads.
• Threads allow utilization to a greater scale and efficiency of multiprocessor architectures.

• There are two types of thread,
  • User Level Threads.
  • Kernel Level Threads.

• In this case, the thread management kernel is not aware of the existence of threads.
• The thread library contains code for creating and destroying threads, for transient message and data between threads, for scheduling thread execution and for saving and reestablishing thread settings.
• From the single thread start the application.

• Kernel is done thread management.
• In the application area there is no thread management code.
• The operating system directly supported Kernel threads.
• Multithreaded can be programmed in an any application.
• An application is supported within a single process.

• Scheduling is an essential part of a Multiprogramming operating systems.
• Such operating systems allow more than one process to be loaded into the executable memory at a given time and the loaded process shares from the CPU using time multiplexing.
• The Operating System maintains the following important process scheduling queues −
  • Job queue − This queue preserves all the processes in the system.
  • Ready queue − This queue keeps a set of all processes residing in main memory, ready and waiting to execute. A new process is always placed in this queue.
  • Device queues − The processes which are blocked due to inaccessibility of an I/O device establish this queue.

• The OS can use different procedures to manage each queue (FIFO, Round Robin, Priority, etc.).
• The OS scheduler determines how to move from processes between the ready and run queues which can only have one entry per processor core on the system; in the above diagram, it has been combined with the CPU.

• Long-Term Scheduler
• Short-Term Scheduler
• Medium-Term Scheduler

• It is also called a job scheduler.
• It selects processes from the queue and loads into memory for execution.
• The long-term scheduler may not be accessible or minimal.
• No long-term scheduler in the time-sharing operating systems.
• Use of long-term scheduler when a process changes the state from new to ready.

• Short term scheduler is also known as CPU scheduler.
• It is used to improve system performance.
• It is change from ready state to running state of the process.
• Short term scheduler is faster than compared to long term scheduler.

• Medium-term scheduling is a part of swapping.
• Medium Term Scheduler has removed the processes from the memory.
• To remove the process from memory and make space to the other processes, the postponed process is moved to the secondary storage.
• This process is called swapping.

• Caching is an area of a computer’s memory devoted to temporarily storing recently used data.
• In caching the content are which includes HTML pages, images, files and Web objects, is stored on the local hard drive in order to make it faster for the user to access it, which helps to develop the efficiency of the computer and its overall performance.
• For example, when a user returns to a Web page they have recently accessed, the browser can pull those files from the cache instead of the original server because it has stored the user’s activity.
• The storing of that information saves the user can getting to it faster, and less time to the traffic on the network.

• When a cache client wants to access data, it first checks the cache. Cache hit is known as when the requested data is found.
• The current of attempts that result in cache hits is known as the cache hit rate or ratio.
• If the requested data isn’t found in the cache a situation known as a cache miss. It is getting from main memory and through into the cache. How this is done, and what data is ejected from the cache to make room for the new data, depends on the caching algorithm or policies the system uses.

• Web browsers, such as Internet Explorer, Firefox, Safari and Chrome, use a browser cache to develop performance of frequently accessed webpages.
• When we visit a webpage, the requested files are stored in computing storage in the browser’s cache.
• Clicking back and returning to a previous page enables from the browser to retrieve most of the files it needs from the cache instead of having them all resent from the web server.
• This approach is called read cache. The browser can read data from the browser cache much faster than from the webpage it can reread the files.

• Some examples of cache algorithms they are,
  • Least Frequently Used (LFU)
  • Least Recently Used (LRU)
  • Most Recently Used (MRU)

• Keeps track of how often an entry is accessed. The data that has to use lowest count gets then removed first.

• Puts recently accessed data to near the top of the cache. When the cache reaches its limit, the least recently accessed data are removed.

• Removes the most recently accessed data first. This approach is best when older items are more likely to be used.

• Deadlock is one of the part of multithreading.
• synchronized keyword is used to make the class or method thread-safe which means only one thread can have lock of synchronized method and use it, other threads have to wait till the lock releases and anyone of them acquire that lock.
• Deadlock can occur in a situation when a thread is waiting for an object lock, that is acquired by another thread and second thread is waiting for an object lock that is acquired by first thread.
• Since, both threads are waiting for each other to release the lock, the condition is called deadlock.

• The Binary search tree is a node-based on the binary tree data structure has the following properties,
  • The left-side sub tree of a node contains only nodes with keys lesser than the node’s key.
  • The right-side sub tree of a node contains only nodes with keys greater than the node’s key.
  • The left-side and right-side subtree each must also be a binary search tree.

• Pre-order traversal.
• Post-order traversal.
• In-order traversal.

• This traversal technique it may be traversal order is root-left-right.
  • Visit the node.
  • Call itself to traverse the node’s left subtree.
  • Call itself to traverse the node’s right subtree.

• Write the program to count number of bits needed to be flipped to convert ‘a’ to ‘b’. For Example given two numbers a = 6 and b = 12; then the output is 2
  • Binary representation of a is 00000110
  • Binary representation of b is 00001100
  • We need to flip highlighted two bits in a
  • To make it b.

• Calculate XOR of A and B.

• Count the set bits in the above Calculated XOR result.

• To begin from the upper left corner of a given framework, one needs to achieve the base right corner.
• Every cell in the grid contains a number, the number may positive or negative.
• We can move across a cell only if we have positive points ( > 0 ). Whenever we pass through a cell, points in that cell are added to our overall points.
• We need to find minimum initial points to reach cell (m-1, n-1) from (0, 0) by following these certain set of rules :

• • From a cell (i, j) we can move to (i+1, j) or (i, j+1).
  • We cannot move from (i, j) if your overall points at (i, j) is <= 0.
  • We have to reach at (n-1, m-1) with minimum positive points i.e., > 0.

• To traverse the tree using Morris Traversal is based on Threaded Binary Tree which means without using stack and recursion. In this traversal, we first create links to Inorder successor and print the data using these links, and finally revert the changes to restore original tree.

• • If current does not have left child
    • Print current’s data
    • Go to the right, i.e., current = current->right

• • Else
    • Make current as right child of the rightmost
    • node in current’s left subtree
    • Go to this left child, i.e., current = current->left

• When the tree is modified through the traversal, it is reverted back to its original shape after the completion.
• Unlike Stack based traversal, no extra space is required for this traversal.

• Linked List is a type of Linear Data Structure that is mostly used data structure after array, which allocates memory dynamically at run time that is it doesn’t require any size initialization as in case of array.
• Linked List stores data in the forms of nodes, which is divided into two parts, first part stores the data and second part points to the next node by storing the address of that node.
• We have first node which contains Data and Address to next node, and similarly second and third node forming a chain.

• To create code, pattern required is: