I've installed Wamp5 1.7.3 on Vista, and when Apache is trying to startup it fails. I found this log entry in the windows log: "httpd.exe: Could not open configuration file bin/conf/httpd.conf: Det g\xe5r inte att hitta s\xf6kv\xe4gen."
The last part is jibberish for: "File path not found", by the way.
Reinstall didn't work, until I decided to go with the default installation path. I wanted to put it in c:\program\wamp, and it used to work well in XP, but not in Vista. However, the suggested path c:\wamp works, so I'll use that now.