csrss.exe

my friend has got a virus named csrss.exe it creates a music folder in d drive and in it creates music.exe when i traced d origin of it i found a csrss.exe file in his msdata folder inside temp folder when i tried 2 delete the file and other contents d file disappeared n den reappeared d hide...

What r these programs, which r essential among these? vsmon.exe alg.exe drqjqk.exe ccApp.exe CCEVTMGR.EXE SPOOLSV.EXE SVHOST.EXE LSASS.EXE WINLOGON.EXE CSRSS.EXE SMSS.EXE Some r new to me.How can I configure these programs to run or not?