I take it this wipe's out all type's of virus's including sneaky ones that anti virus programs can't detect or remove ?
Also if you want to avoid virus's stick to safe websites or if you feel the file sounds dodgy then it usually is lol
Also scan ever RAR archive file you download to check for extar security and Like I do scan your whole computer everytime you download something that way you never really get virus or if you do you catch them before they spread into system files.

I had a virus as aggressive as this on my old computer think it was a hydra that came through a backdoor virus and literally let 20 trojans in and a generic and they all wrecked havoc like basically went to war on my comp lol took away most system files so I couldn't start to heal my comp or nurse it back to care then continued to fuck shit up.
I just factory restored my comp, thats all I could do and just started over again at rebuilding my file collection

Not always, they can be files that you havn't deleted the source file from, like for instance say I have a game that I have downloaded and it saves the RAR archive file in my downloads folder or whatever and take all the files out from there and it makes another folder on, lets say my desktop, then the root archive file will still be on your computer after you have deleted the stuff you have extracted, You should always remember this if you are a clean freak on a PC like myself lol because if you just delete files and not there the root downloaded file then you still have it on PC. You can also do a disk de-frag if your files keep coming back (this also cleans up fragments of files and compresses down your files you still have stored) or Re format you hard drive **ONLY USE THIS METHOD IF YOU KNOW WHAT YOUR DOING OR HAVE ALL YOUR IMPORTANT DOWNLOADS/FILES ON A EXTERNAL HARD DRIVE**
If it keeps happening then i would give you comp a full virus scan because it could be spyware (which isn't so deadly unless you do online banking or such things were you credit details go into your computer)
I would still give your PC a full scan though and keep doing it every few days just so your pc is always being checked and also some virus progress so If you scan your pc every few days some can be healed from your PC before they have a chance to get into your REG files or system files

If you have any error messages or warnings or any clear cut questions then feel free to ask me and I will try my best at helping you ace

Haven't been realyl playing it been playing CV on the DC more and some RE5 mercs online lol
I have completed and done everything on RE4 before anyway I just felt like I wanted to play it again and I
Think I am at the bit were you first meet the merchant lol