Sudden extremely bad lag on my PC
This has been happening for a few days now. I can usually run any Steam game full resolution at medium settings and get around 30 FPS. However, for the past few days it's been really horrible. On TF2 now on absolute minimal settings, 640 x 480 with "very low" or "no" set on everything. I won't get any more than 10 FPS. And it isn't my internet connection either, all of my other offline games act in the exact same way. I've tried running a deep virus scan, nothing. Disk Cleanup, nothing. Disk Defragmenter, nothing.
This has completely ruined my gaming and I need to know why it's happening in the first place.
BTW, I've got a 2.79 GHz processor and 2 GB of ram. I've got an outdated graphics card, but that couldn't be the case because it's been working just fine till now.