(removed on user request)
Someone posted this on my Facebook page, and I clicked on it, and it brought me to YuoTube (that's how they spelled it). I'M SCARED.

It's a message from Teh Lawd. If interpreted correctly it should read: We apologise for the inconvenience.

I wouldn't recommend the paid version of Avast!; paying a yearly fee for a couple of extra features isn't a good deal. You can easily match those additional functions by simply taking sensible steps online.
If you're looking for a good firewall to accompany Avast! I'd recommend Comodo Internet Security (free). It will occasionally pop up "Defense+" messages asking you to confirm certain program actions (such as elevating an unrecognised installer), but unlike Norton 360 it has an expansive whitelist of safe files and trusted digital signatures to let known programs do their thing without any user intervention. The new version has a sandbox feature that automatically segregates unknown processes to prevent them having full access to your system; games won't run correctly in the sandbox, but neither will malware (removing programs from the sandbox is easy). If you mostly use signed and/or well-known programs you will see very, very few prompts with this firewall.

Thanks for the advice! I am now running House Call, to see if that picks anything up. Avast! is still searching.
EDIT: House Call didn't find anything! Should I be worried?

I second Comodo, a little busy first day or two but once it knows your system you rarely hear from it unless it's necessary.

Commodo has a good firewall but I found Defence+ pedantic and the AV is more than a bit paranoid. But the firewall by itself is good.

Let Avast finish, if it doesn't find anything, you're probably good.
Oh, wait, Avast? I'll have to change one of my posts above then. I've been running Avira for the last 5 years, not Avast. Back then Avast had worse detection rate than most though it's improved and I am currently giving it a try again on my stationary machine.

hijackthis is your friend! Find a good security forum and post some various logs and describe how you got the virus there and they will help you get rid of it.
Quickly googled some forums:
http://www.security-forums.com/viewforum.php?f=48
http://www.bleepingcomputer.com/forums/forum22.html
Quickstart (but the forums probably got it too):
http://www.whatthetech.com/hijackthis/
I would advise that you didn't use sensitive information when registering accounts there... just FYI... good luck :)

Defense+ behaviour is improved in CIS v4, and alerts are now very rare--I have only seen them when running unrecognised installers or when a known program is used by an unknown one in a suspicious manner. There are also far more whitelisted processes and digital signatures included with the program (programs that are whitelisted and/or have recognised signatures silently bypass the sandbox and Defense+ without any user invervention).
As for the AV they seem to have improved it but I'm still sticking to Avast! for the foreseeable future (I have the Comodo AV installed but disabled to give me the option of a second opinion).

Thanks for the heads up. I have version 3 and despite checking for updates the existence of version 4 was never brought to my attention.

DOH! How could I forget Hijack This?!
RUN IT!!!

Hummn, I run ver 3 and no indication of a ver 4 here either. Never tried the Comodo AV, use AVG in combo with Comodo, trouble free for years.

Uhh, he should ALSO run spyware scans after virus. Just to be sure. AVG/Comodo/Avast will not detect spyware/adware/malware, only viruses. Grab Ad-Aware or similar program, and run that, and then consider yourself lucky, if nothing is found.
Also, look for "QFX software's KeyScrambler" and install that - it's a util that encrypts your keystrokes online at the kernel level, so IF you do get a keylogger, it can only read the encrypted keys, not the actual password. free and paid versions available.

Avast! scan completed. It said 0 Problems Found, but it also said "SOME FILES COULD NOT BE SCANNED"
Greeeeaaatttt...

Are you still having issues with a system restore?

That's usually the pagefile and a couple others hat are in constant use.
Can you get a list of exactly which files could not be scanned?