Yesterday my pc with vista got infected with 6 trojans and viruses?

My avg detected them, and I downloaded other antiviruses and trojans and detected them also, but when I removed them it appeared again seems they were spreading into other files.

I disabled system restore as someone said, if you deleted the virus it could come again because is hidden in system restore, still sign of viruses and trojans. I went on Safe Mode, scanned it, and AVG didnt detected anything and the other programs didnt work, I restarted the pc, and the screen got balck and froze.

I decided to put my pc back to factory settings because is a dell, and reinstall vista using that feature before I lost my pc.

I scanned my pc earlier and there is no sign of viruses/trojans

but now I can again and it it says there are no threaths BUT

while is scanning two files appear below File

user32.dll

shell32.dll

ntoskrnl.exe

and below Result/Infection is says in all: Change

and bellow path that it belongs in system32

What that's suppose to mean? It havent detected viruses but that a

Yesterday my pc with vista got infected with 6 trojans and viruses?computer protection

Your situation is normal for AVG, the keyword here is that ''change''. Not infected.

''The changed files are normal. I happens when you update certain parts of Windows and when the system repairs files.''