Well there has been a problem with my PC since few days.
My system with a flat screen,2 RAMS,Intel Motherboard,No Video or Graphics Card,2 Hard disk- One of 80 GB and another of 500 GB,Windows 7 Ultimate.All data on my system is safe.I transferred some data from my friends' external Hard drive few days back so I think some virus has attacked my system.
I am going to explain what happens.
When I press start button on my CPU,it normally starts and the fan inside on the motherboard is running but the fan in PSU starts like zrrrrr..... zrrrrrr..... zrrrrr..... for atleast a minute and then it runs normally.
Now the desktop starts for 4-6 seconds and turns yellow which means nothing shows up on screen.Still the system is running.
When I press Alt,Ctrl,Del simultaneously the desktop starts again for 4-6 seconds means the same problem.
When I take out CMOS battery and insert it again-the same problem.
When I interchange both the RAMs(1 RAM of 2GB and another one of 512Mb)-again the same problem.
Few days back prior to this problem,the mouse was not able to work and the screen was facing problems of displaying nothing and displaying normally(this happened almost 3 times in every 30 mins)while watching movie(Pulp Fiction-wow I loved this movie) and doing other tasks.And I was working with just arrow keys the mouse was not working.Last night fortunately when I started the system anyhow with pressing Alt,Ctrl,Del and F8,F9,F10,F10 all at once.It started and I noticed all the data were safe and mouse was working properly and keyboard was ok too.And Again the same problem happened.
(I don't know how to do BIOS settings by pressing F8,or F10 etc)
What should I do?