To cut things short: -
- Installed Windows 7
- Had welcome screen disabled by default (i.e. you turned on the machine and it booted straight into the desktop)
- Installed Visual Studio 2008
- When booting the machine, it boots to welcome screen and waits for me to select my account
I've noticed this before on Vista/XP, I think it's something to do with the .NET stuff VS2008 installs but to solve it you just had to go into the control panel, select "change the way users log on and off" and disable the welcome screen.
I can't seem to find this option in Windows 7.