I have used this for XP 32, Vista 32 and Vista 64. I don't have a "real" W7 yet, VM only.
I ran under W7 VM with no problems. It is unknow if I "fixed" anything.
Here is how you use the tool:
1. Drag connection speed all the way to 20000 (or you max DL rate)
2. Check "Modify all Network Adaptters"
3. At bottom, highlight "Optimal Settings"
4. Apply Settings.
5. OK.
6. Reboot.
and, enjoy!!