editing or coverting first?

[Confused Chimp]

I'm looking for some help.
I'm using my computer to do a few camptures over a long period of time. I am expecting the orginal captures to be around 300gb AVI file (using VirtualDUB)
The amount of footage I will want to keep will be a lot less.
My question is should I convert it to a WMV (using windows media coverter?) first and then edit it? or should I edit it first and then covert it?
If I do convert it first and then edit it and then save the final footage will it loose quality twice or will the quality stay the same?
Hope that makes sense
Any help most appreciated.
Cheers
CC

[gadgetguy]

Standard rule of thumb: Edit first, then encode to maintain the highest quality.

It is possible to edit encoded video, if all you are doing is simple cuts and your source material doesn't require frame accurate cutting. There are some editors that will allow frame accurate editing, but they will re-encode for a few frames around the cut point resulting in lower quality (although it may not be too noticable). Most of these editors are designed to work with the compressed video because it's assumed you don't have a choice in the source.

[mats.hogberg]

In what format is your original?
No matter, edit in as uncompressed format as possible - DV avi is good.

/Mats