I've been having a peculiar problem. First, setup: WAMP 2.0 on Vista Business Edition.
In the course of trying to set up rapid development environments on top of WAMP, I've been flustered. It seems that whenever I tell WAMP to "Restart All Services" . . . Apache refuses to restart. I can get around this by re-installing WAMP, but you can imagine how much of a pain that would be to do every time.
Nope, since port 80 clear doesn't mean your wamp can run becasue it still depends on some other factors such as: already had webserver before, antivirus/firewall block wamp, apps conflict wamp, so on
Check if you have any in this list: IIS, Skype, Zone Alarm, NOD32, Eset, Internet Optimizer, Google Accelerator, or any other web server, so on