Phatrat, Here's a link to AVS where there was an entire thread devoted to burning HD onto a standard DVD. Surely this statement will bring out somebody who says it cannot be done. But, yes it can, and I have done it.
Some problems I can see for you is getting the VIDEO_TS stream data out of your DVR and into your computer. I don't do any cable or Dish or Direct thing. I am strictly an OTA guy. And with OTA there is no encription issues with the recorded material. So you will need to find someone who can help you there. Second problem will be that althought one can create a SD DVD that will play HD material at HD resolutions on a Toshiba HD DVD player, the cost of the required programs are such that unless you have them you will probably end up spending the cost of a BluRay player.
Here's the link:
http://www./avs-vb/showthread.php?t=705146
IMHO HD DVD was a better format in that allowed one to create their own HD discs from recorded programming. I have not done a HD DVD since the defeat or abdication or whatever one wishes to call Toshiba's decision. The process isn't a quick one and had HD DVD survived I think a transmogrifier program would have been developed to make the process simple. But read the thread and give it a try if you feel it warrants your energy and time.
Bests,
Wiley