Oh a couple of times a year, but normally a course of penicillin does the trick
Usually I'm fairly satisfied with my self-built rigs. For example my Q6600 lasted me thee and a half years, at least three years of that at 3.6ghz.
During that time it had three GPUs (8800GT, GTX 275 and a GTX 570) it had it ram doubled from 4gb to 8gb, had its Freezer Pro cooler replaced by a Titan Fenrir and, finally, went from Windows XP Pro, through to Vista and finally Windows 7. So, a gradual progression of upgrades throughout it's life.
My "whim" purchase of a Sandy B. bundle has been a little different so far:
Motherboard changed from an MSI G45 (problems problems) to the far superior ASUS P8Z68-V Pro - old board RMA'd due to numerous faults and issues. Antec Kuhler retained but better push/pull fans added. PSU upgraded from CM GX650w to a Corsair HX750w. 2nd GTX 570 added.
Currently I'm slowly planning out migrating the lot to a TJ07 case and water cooling it all - that's going to be a longer-term project however. I
might end up with a Sandy Bridge E before it's finished lol.
In the interim with these two main builds however I've upgraded my gateway (old gamer) built a media PC, built a spare backup box from and old AMD 4200+, re-cased an old old Sony Viao P4 3.4HT system as a spare spare and build a basic box for my mum to use...so I've kept busy enough that the itch hasn't bothered me too often
*
Cheers,
Scoob.
* Evidently because I'm keeping it regularly scratched 
