I re-installed EQ5 on my newer computer a few years ago. Forget what operating system is on that computer but it is newer than Vista. The only issue I have is that I frequently can't see blocks I've saved in the sketchbook unless I close down/restart the program. When I did the re-install EQ5 said the graphics would not work and initially they did not. Restarting the computer fixed that issue.
I would think you could save your tracing in your sketchbook midway through the project. I do that frequently if I make a change to the quilt or block I'm working on.