Okay. Now it's just getting silly. (computer problems)

[chiasaur11]

Stop me if this isn't anything.

But...

My computer is still seemingly insane.

It had other problems, documented previously, of course. But the two main ones were: Slowdown on Valve games for no reason (that wasn't happening when I bought the thing) and space actively disappearing when I defrag, then reappearing for no reason days later. Tried antivirus checks. Nothing.

Tried changing drivers: Nope.

Tried a full reboot. Nah.

Got it cleaned. Nada.

Tried to get it checked at best buy: THE COMPUTER DISAPPEARED FROM THEIR RECORDS.

Finally, I mailed it in to the company, a week before the warranty expired.

They replaced the hard drive and sent it back.
The defrag thing is still there. Is that because it's a non issue, or because there's a serious problem that nobody seems able to do jack about?

[Starscream]

Tried to get it checked at best buy: THE COMPUTER DISAPPEARED FROM THEIR RECORDS.?

Clearly your machine has become sentient and removed all record of itself. This is to prevent some clever Best Buy employee from realizing that they have just sold you Skynet and alerting the authorities.

The space disappearing and then reappearing suggests that while defraging, the computer created a bunch of temporary junk which it then kept around. Later on the data expired, so you got the space back.

This probably isn't a problem, but if the space is still gone, run Disk Cleanup (I'm assuming a Windows machine) and see if there's a big chunk of unnecessary Temp files that you can get rid of.