7stacks by Alastria comes highly recommended for Windows 7. I've installed it on Windows 7 64 bit Ultimate. When I run 7Stacks, the cursor turns busy for maybe 10 seconds and nothing else ever happens. The task manager will show that 7Stacks is running in memory, but there's no user interface, no menus, etc. Does it work in 64bit? It's a 32 bit app.
UPDATE: 7Stacks seems to have a problem if your DPI setting is not the default 100%. The authors have been informed.