I had absolutely no problems updating with Windows 7 on both the Deam and Magic.
I did not follow the instructions, just downloaded, installed and worked like a charm. Checked the instructions after reading this post, and they were very clear. Easy for the standard user.
Really? It failed for me and almost bricked my phone trying to update with Win7 64bit. I had to bust out my old comp and blow the dust off it to do the update.
Edit: After further reading of others comments it appears maybe I just needed to leave USB debugging on, as I did already have the (non-rogers/latest) Win7 supporting HTC Sync.