How can we run IIS 6 and Apache (wamp) in same machine at same time?
IIS and Apache should have different port.
To change the port of Apache(WAMP)
Find the "80" then change
Listen 80 to Listen 8080
ServerName localhost:80 to ServerName localhost:8080
Note: You can change the port which you desired as long as it will not conflict with your other port. It is more safe and common if the port is at this range.
Then click on Restart All Services.
See here for more info.
If you prefer to change your IIS rather Apache, check on this IIS