Software Applications Programming Errors and solutions.

1. Do NOT open any Email attachments from unknown sources like exe files , whether on your your own personal email accounts such as Yahoo, Gmail, etc.  2. Do NOT click on any Links , sent from unknown sources, either via Emails or accessing your Facebook account.  Also, please refrain from accessing unknown Web Sites.  These can be infected with Ransom ware virus 3. Do NOT Disable your Anti-Virus under any circumstances . 4. Take regular  Backup of all your important Data and files . 5. Update all Patches - Antivirus, Operating System ,soft wares,Internet explorer etc MS Office, etc. 6. If you are unable to open any of your files that you use, please follow the instructions    If you notice any suspicious activity on your pc / laptop / laptop is running too slow, immediately disconnect your laptop from the network, shut off your pc / laptop 7. If you use / share any External Drives such as USB Thumb drives ,USB Hard Disks,CD,DVD etc please SCAN them with the Antivirus bef

What is Virtual Memory and How it works? Virtual Memory allows multi-user as well as multi-programming computing environment that too for very less RAM. RAM use to be very costly earlier compare to present day. CPU has PC register from where next instruction can be fetched or data can be load/store. Assuming PC being 32 bit register, it can address 4G locations. But practically we put very less RAM, say 128MB only. Assuming Virtual Memory exists, compiler generates code for an application, where compiler is also aware of OS+Architecture. Now code generated by compiler assumes entire 4G location (so large extent) is available for it and it is the only application running on the CPU. So PC register shall always issue address which is one among 4G locations. So this 4G which is in fact physical capacity of PC register of CPU, is used as Virtual Address, as actual RAM is much less (0-128MB only) Now OS uses a table call Page Table along with MMU unit of CPU. Using this it loa