I currently have VS 2008 Web Developer SP1 installed on my machine and I've purchased the professional edition. I also have 2003 and 2005 Pro installed.
Should I un-install VS 2008 Web Developer before installing the professional edition? If not, will I have two version of VS 2008 or will Professional "Upgrade" Web Developer.
Please note I haven't bought an upgrade license, I have the full license for professional.
Web Developer is a separate product to VS2008, and the install shouldn't change it.
As an aside - with the multi-targetting in VS2008, you might want to save some space by uninstalling VS2005? VS2008 can't target 1.1, though (except maybe via MSBEE) - so maybe keep VS2003 if you still maintain 1.1 code. Obviously, if you do this: first make sure that VS2008 supports any legacy requirements you need... (i.e. don't blame me if you can't edit your project!)
I would probably uninstall Web Developer first, but you might find it handy for small test projects? I keep C# Express installed for the same reason (I find it quicker for small scratch tests).