I have been trying to runn the RUU on my 64bit windows 7 pc for the last three days, at one point it finally saw my phone, connected and began running the ruu (I was excited) and then about 2 min later it again errored out!! at which point i never was able to get it to connect again!!! I installed HTC Sinc but it made NO Difference, I was so ****ing frustrated!! ...
I downloaded cleaner as yo said, ran a full clean and then a registry clean after uninstalling the HTC Sinc software
I then re-installed HTC Sinc connected my phone to my pc, ran the RUU and (NO LUCK) ..... IT was getting hopeless for me and I was tired of waiting for the OTA update, not just because I wanted it, but my phone was acting quirky and was totally hoping that Froyo solved some minor issues....I almost gave up but I then re-started my PC, connected my phone, turned off wi-fi on my pc, eneabled USB Debugging, started the RUU and (BOOM) ...everything started to work....FINALLY!!! ..... I am now running Froyo
So thank you very very much... Your the man !!