No applications or file extensions run anymore! HELP PLEASE

I just turned on my computer like normal and tried running applications like Firefox and iTunes and nothing happens. I try using the desktop shortcuts, toolbar icons, and under start--programs, still doesnt work. THen I tried running file extensions such as a MP3 file or AVI or MP4, those files wont open. I tried using programs like malware bytes, FACE from MRI PE, they found errors and traces but i would kill them instantly, restarted my computer many times and still same issue. Please Help.

i cant do a system restore because no restore points have been created past last night when this problem began. and I tried doing the file association it didnt do anything. It's weird because only the programs I use the most and often are the ones not working, right now im using my IE X64 and thats working fine, but my programs like iTunes, VLC player, FireFox arent working, and any file I want to open, wont because theyre associated with those programs. Though i tried using a different application to open the files and i get a "server execution" error.

Sounds malicious: Maybe save your important stuff asap?
Scan with brink's link then see what happens.

Just finnished the scan and i got 0 infected files. A clean install is the last resort. I do not have the installation disk to do a repair install. I Have about 727 GB of files and stuff on my computer that would take a long long and expensive time to do a clean install. I'm sure theres a way to fix this issue other than formating the HD or doing a clean Install. I think i read somewhere it could be a RAM or memory problem. how could i scan that and fix it.

THis happened to someone else recently. I was due to uninstalling an oldish program file that hosed the registry. Thier fix I believe was a system restore though

Did you do something last night like install or uninstall something? You said there was no restore point "past last night", does that mean there is a restore point for last night or somthing? Are there any at all?

whow just found something new. what is this "BrowserModifier:Win32/Zwangi" it just poped up this on my screen

And no there is 0 restore points past the time of the problem. I manually created one last night but i tried going back to it but the problem was still there. Its weird because i cannot open ANY media files at all. This all just randomly happened i didnt install anything new or download anything it was just a matter of turn off and turn on the computer. but what could that new thing i just found be i posted a min ago