The issue is already solved.
Either deinstall update KB2670838 or deactivate the thumbnailsystem.
So if this tinkering with autorun programs stops the memory leak on your system I am wondering if you have KB2670838 on your system (is also part of IE10) and a 3d-mp4 and can see the thumbnail instead of the media icon for this file.
--
If you expierience a "slow" system with an 8-core and 32 gig ram in a way that tinkering with autostart programs gives you a "faster" system, I strongly suggest buying a ssd.
I transcode Mediafiles (uses all cpu it can get) while recording several tv streams (heavy load on i/o, for the data hdd) and my office expierience is not impaired. No little lags or stutters or what else gives the feeling of a "slow" system. This is on a quadcore with "only" 7 gig + 1 gig for the onChip graphic with os and all non-data on a ssd.