So, I got my new 550D. I understand this shoots video in .MOV

How on earth do I do anything with these clips? Nothing supports .MOV at all. Im also reluctant to use any little converters because it's going to strip the quality of my video's. All im wanting to do is put my video's onto some editing software and make some short movies but not even the infamous windows movie maker will take my clips.

Getting quite frustrated, can someone tell me exactly what I need to do to make these videos usable in editing software? Also im using windows not mac so I can't use FCP.

MOV is a specific wrapper, an envelope format for the basic H.264 codec video and the audio.  You might want to look at mp4cam2avi.exe, freeware available here:

http://mp4cam2avi.sourceforge.net/

It will re-wrap the MOV content into AVI format without re-encoding anything, so there's no quality loss.  Then you can edit it in a wide variety editors.  But you still have to have the H.264 codec installed, perhaps from the FFDShow codec package.

I think it's a performance issue. I can't play them on my computer either. The movies are fine if you process/export them though.

Exactly. If you use VLC and go Video-Zoom-Half does it work then? It does for me. Depends on your CPU and graphics, though.