So, I had my Studio XPS 8100 for about 2 and a half years now and recently I decided to reformat and clean my tower (Taking it apart, blowing off the dust etc). After installing my drivers, I decided to play Crysis again. Strangely, my computer lags on High (FPS drops/ choppy) and drops occasionally (although not often at all) on medium. 2 and a half years ago, I was able to run Crysis on High settings without any lag at all. Now, the ultra high setting is no longer select-able, 2.5 years ago it was.
Both ran on DX 10.
You computer cannot decay. If your PC is spontaneously crashing or BSOD'ing, you might have a hardware issue.
Take a look at any programs or services you have running in the background. Anti-virus software or even viruses themselves can slow down your PC.