Thankyou so much for your reply
I did the memory diagnostic scan but it found no errors
Bitdefender online scan reported no infection.
There is no folder named minidump in windows.
And no file named memory.dmp
And i set the system for a minidump as directed in the link.
and i found another thingy: when I start CMD, it says
"c:\windows\system.bat is not recognized as an internal or external command"
I dont really understand these computers myself but i suppose the virus might have ruined some system file..and ya i even tried reinstalling the drivers
-but that too proved futile.