BleepingComputer.com: I have a virus

Problem:PC goes very slow,can't erase files (most of them),because it says they are used by another application.

I've done a lot of scans with different antivirus,but no virus are found anymore.Its weird,cos some were removed,now it says the pc is clean but still I have this problem.I've tried to reboot but still it doesnt let me remove the files.
It also says when bootinh that it can't read BOOT.INI and it starts from C:\WINDOWS or something like that.
If you need more infos,just ask.
Thank you!

Boot into "safe mode" by tapping the f8 key whilst booting your computer. This will reduce the number of programs and applications accessing files to a very minimum; run your AV.
Regards,
John

Thank you,I'll let you know if it doesnt work.
Anyway my AV doesnt detect anything in normal mode.