Consistency check freeze and fail

I have an Acer Aspire 6920 purchased in Nov. 2008. I upgraded to Windows 7 last May.
Recently (the past month or two) it's been having issues like overheating a lot freezing multiple times in a row despite not being hot.
Even more recently (last few days) it has a weird screen on startup saying that there might be a problem with the C: disc and running a consistency check on the hard drive is recommended, Press any key to skip this check, then it proceeds to count down from 10.
If left alone, upon reaching 1 the screen just freezes. Nothing happens, it doesn't run a visible check of any kind, even if left for an hour or more.
It also doesn't recognize any keystroke to skip the check. I can spam my keyboard to death and it continues to countdown and freeze.
So far the only way to fix it is to reboot the computer multiple times in a row and hope that it bypasses the message. Sometimes it takes up to 6 reboots for me to get lucky.
I've also tried to manually run the consistency check, by going My Computer => C: => Properties=> Tools => Error Checking => Check Now but it can't run the check while the computer is running so it schedules the check for the next restart, and we come full circle.
A few other things, I'm not sure if they're related:
C: drive is no longer and option for Disk Defragmentation. It just does not appear on the list of drives to defrag (my solution to everything)
I've also been a victim of some of the new malwares: Win 7 Home Security 2011 and AntiVira Av. I used MalwareBytes to get rid of both, though a friend thinks that they might be contributing to my problem now. He also suggested something called combofix.
If anybody has any advice or experience with the problem, your input is more than welcome.
Thank you.

 

Greetings, MissTeri.

Your friend is correct: the malware could very well be contributing to your problems.

If possible, I strongly suggest you go through the Malware Forum's Read & Run Me First thread, perform all of the suggested steps, and attach the requested logs to a new thread in that forum, just to be safe.

As far as the C: drive, I suggest you begin preparing to salvage any important data asap in case the drive is failing.