It's important that it won't leak memory too much, and that it would be fast enough to allow reasonable terminal based work on the PC.
How about Cygwin/X?
When I was on MS Windows XP, I found Xming to be quite stable, manageable and not resource-hungry.
Have a look at ciXwin, a standalone solution packaging all Cygwin/X base stuff, fonts and ssh into a small and convenient installer (about 30 MB). ciXwin is designed for displaying remote clients via ssh. It is free for use and distribution under 2-sentence BSD license.
Disclaimer: I am the developer :-)