Hi,
I'm glad you found the KB article about the directories.
What is your system's memory and CPU speed? Running Vista, you'll need more memory than with other operating systems (1 Gb minimum) and the speed of the CPU will affect how fast any program runs, especially one that relies on video and audio such as Composer does.
You can try turning off any other programs that may be running in the background to free up memory and CPU resources. (On my old machine, any time I did any audio work I'd turn off everything else, even my printer stuff because it "pings" the system to see if there is anything for it to print.)
If you have minimal memory (512 Mb), then you can try upgrading the memory - it's one of the cheapest upgrades you can do for a computer. And it will make everything run faster
Let us know if the above suggestions help or not.
ttfn,
Sherry