Windows 7: WMC playback choppy and CPU Usage drops to 0%

When I watch HD video in media center either live or recorded i get choppy playback. Once playback goes back to normal or live tv stops skipping I can rewind and watch the video without any problem. This was a Vista machine and i thought a update to windows 7 might help and it did not. I added WMC to the Norton list so Norton would not run background scans while WMC is being used also did not help. No other programs are running while I am using WMC. I opened device manager and watched CPU usage and noticed that when ever the jerky playback happened the CPU usage would drop to 0 then up to 3 then back to 0 up to 6 back to 0 and so on. Once the jerky playback stopped CPU usage would be between 1-15% mostly between 3-7% but never at 0% while playback was good. Any Ideas? I am not really a computer guy so not sure what else to look at any help would be appreciated.

Here is what I have
Gateway PC
Windows 7 Home premium 64 bit
Intel Core 2 Quad Processor Q8200 2.33 GHz
8 Gigs of ram
Geforce GT120 video card

thought I should add that the sound plays perfect the whole time it's only the video that is choppy/jerky.

Anyone??

To rid yourself of the old problem, start new.
Format the system and clean install Windows 7.

The installation DVD, when booted,
will give you the option(s) to delete an exisiting partition and create a new one.

Sometimes, issues like this could be caused by a highly fragmented drive.
Or, possible something making heavy use of the HD in the background.

Since this is something that can be easily remedied, have you tried defragmenting the drive?



Sadly, if there were a few issues with Vista, and you simply done a in place upgrade to 7, chances are those problem were just carried over to the new installation.

The best way to upgrade, and be certain no other possible issuies are carried over, is with a clean istallation. Which means formatting the hardDrive and starting with a clean slate.
Just be sure to back up any personal DATA you do not want to loose first.

Yeah a clean install gives you less problems than an upgrade install. Just make sure you backed up your personal data and your drivers.

In my experience, WMC gets a little smoother when you defrag your drive and begins to get laggy a bit if you haven't defragged your disk for a while.

I have defraged multiple times with no luck. I don't have any thing on this computer other then a couple recorded tv show's I will watch then and try a clean install. I'll let you know how it turned out.