Stability of video formats

I want to know the most stable form to store video files till they are recorded. I record shows using MS WinXP MCE 2005 in .dvr-ms file type, and normally I edit them (DVR Edit), then convert them to MPG (AutoDVRConvert) and burn them (Nero 7 Ultra Edition).

I'm wondering if I would be able to safely store them if I converted them to .wmv (or a different file type), then edit (MS MovieMaker), and burn (Nero 7UE). My concern is that there may be transcoding errors or other issues that arise over time that would corrupt the file (more so than leaving them in the raw form) enough so it couldn't play on a DVD player w/o errors. I just fear that since .wmv are MUCH more compressed, it may be more likely to get errors or have errors during transcoding. As it stands now my HD becomes fragmented and can cause errors anyway. If anyone has a suggestion of software to reduce transcoding/DVD authoring errors it would be appreciated, I prefer freeware. I've tried Arcsoft ShowBiz DVD 2, Sony Vegas, VideoReDo, and Pinnacle Studio 10...none are worth their price tag to me.

If it is better to store as .wmv or makes no difference, does anyone know which dvr-ms to wmv transcoder is better (DVR2WMV or WMV Transcoder)? WMV transcoder I downloaded from this article about ''Fun with DVR-MS'':

http://msdn.microsoft.com/smartclient/default.aspx?pull=/library/en-us/dnxpmce/html/dvr-ms.asp#dvr-ms_topic7

Thanks in advance.