Windows 7: What can I use to edit Win TV HD files?

I'm looking for a reliable program to do this with. Do you have any suggestions? I have searched it here but I can't tell what will work for sure.

What file extension are they saved in?

.WTV

Sorry, I have no idea. They're probably encrytded anyway,

Please use the forum search feature to find answers to common questions. You will likely find your answer.

Additionally, it depends greatly what you want to do with the converted files, i.e., reduce file size for archive, burn a DVD for personal playback, edit out sections of the files...

You can burn a DVD with Windows 7 WMC with supported hardware.

You can also install Windows Live Movie Maker or use one of many utilities noted here in the forums, carefully reviewing each as many seem to make unwarranted or unnecessary changes that can affect playback and are not supported by MS.

The files also need to be 'open' or unprotected by the original content providers. Here in the USA, most HD content available thru cable and satellite providers is protected. This protection is included by the content providers and their protection enforced by MS in order to allow the DVR (record) features found in WMC. Using third party software to edit, modify and specifically distribute this content can lead to legal ramifications.

Yes, I searched it, and was unsure of many of the answerers. I have live movie maker, and that won't save it. I am recording over the air HD through an Happauge 2250. All I want to do is chop off the beginning and end of each program, remove the commercials, and burn it to it's native resolution, which in most cases is 1080 I or 720p. I have no interest in recording a film, and trying to cheat on buying it on DVD because the resolution still isn't up to a Blu Ray anyway.

Windows Live Movie Maker is about as good as it gets at this stage.
Once you've edited out the ads and trimmed the movie to how you want it, click on the Movie Maker icon in the nav bar - next to the home tab. Scroll down to save movie and choose burn to dvd, or just click the DVD icon on the nav bar.
Alternatively, you can also save the movie in it's native resolution using the selections in the save movie menu options. I believe that both 720 and 1080 files are saved as .wmv files, so they can be quite large, make sure you have plenty of drive space!
We're you getting any error messages when you tried to save using WLMM? Just wondering if it could perhaps be the directory that you were trying to save the movie to... Windows 7's security restricts access to important folders.

convert to dvrms and use lifextender to remove the commercials

Thank you both for answering, and I hope you had a nice Thanksgiving. Maybe we should take this one step at a time. If I can get MM to work properly, for now it should be able to do most of what I want. I was finally able to import an hour long HD WTV file in to Movie Maker, and clip it down to 30 seconds, just as an experiment. I saved it at 1280 X 720. It played o.k. THEN I tried it again with the same original source, and other files and it crashed saying: "Moviemaker can't save your movie using the selected profile...... 0x0 something." Now this has started to happen no matter what file I use, or what size I try to save it at.

For the sake of sanity, I'm just using 3 min long original WTV HD files, to speed the process up. I'll split them just to see if I can save them. I don't know why this is happening at all. I've tried both splitting, and clipping the files, and I get the same result. The box comes up saying, "Saving movie" it sits there, with no graph moving, (appears to be frozen) and nothing. 45 minutes later I give up and kill it off with task manager. Hitting the X or, "Cancel" doesn't have any effect. It's a complete program hang. Other programs will work while this is happening, but not Win MM. I see nothing unusual in the Task Manager, which is the only way to shut down the program after this happens.

There is also a sound issue that I will bring up if we can solve this problem first.