I think i have a persistant Virus

[Platinum Pete]

I am using AVG and windows XP firewall and i did a virus check the other day and it brought up 6 entries all of them trojan horse all of them in the windows folder. they were all succesfull removed (apparently) but im occasionally getting AVG automatically warning me of more viruses found. I never had this before

Is this a persistant virus or are there just more attacks coming in lately. also they come without me even downloading anything. is this normal??

What can these viruses actually do to my PC, is it safe to still use internet banking if my system is continually infected.

Please help...

 

[Platinum Pete]

turn off system restore, then run AV, (i'd reccomend against AVG, it misses a lot.. use the nod32 trial or pay for nod32)

and run Windows Defender (made by MS and is VERY good)

Why do i need to turn of system restore?

also nod32 demo: how long does the trial last?