It appears to be safe, just a screenshot pasted into a .doc file.
cbkitt: the Windows 7 clipping tool will save clipped screenshots as image files, which most people are more comfortable opening than .doc files which could contain malicious macros.
To get back on topic, I just successfully used the windows live movie maker to convert the original wtv file to a wmv, then used Super to convert to a decent avi. not ideal as it's a 2 step process, but it does work. I'm going to try out Handbrake next to see if it works.
Using windows media centre, scroll to tasks, and burn your wtv as a dvd f you want to watch it on another device (without editing)
I'm still searching for a free way to edit the wtv file and convert it to something more supported, will keep you updated if I find anything.