I’ve been troubleshooting an issue with Windows 7 setup on a specific hardware model in MDT with a hodge-podge of a particular vendor’s drivers in the driver store, and I ran into a little issue with Windows 7 setup debugging that I thought I’d share – it doesn’t seem to work right on the first try. It will connect, then almost immediately disconnect the remote debugger. If you simply leave the debugger running and attached (in my case, to COM1) and restart the debuggee, it reconnects properly the second time.
I still have no idea why this happens or why it’s so reproducible, but I thought I’d share. Oh, if you want to do debugging during setup, simply press F8 before the splash screen and select the debugging option from the Advanced Boot Options menu, similar to what you can do in a full Win7 install.