I was going to go on battle.net to discuss my map with some SEN dudes, but my computer is (as always) being used and TZ's computer (which I'm on right now) is on patch 1.15.1. When I connected to USEast, it downloaded the patch, but BSoD'd halfway through. When I restarted it and tried connecting to USEast, it started the download from the same point, finished it, and said it would restart SCBW. Instead, it went back to the gateway selection screen and gave me an error message about "The user has not been authenticated" or something.

TZ's at school right now (I'm sick, so I'm not), so I can't do much. I don't want to break his computer...

Just reinstall SC...? Use the CD or just dl it off his bnet account (or torrent it).

That would put it on the first patch and I've have the same problem. Plus I'm not going to mess with TZ's computer to that extent: If I break anything he might not let me use it any more.

Just download an 1.16.1 patch from Blizzard's site and install that.

IIRC the only way to fix the way TZ downgraded was to use the Brood War AI downgrader.
http://www.broodwarai.com
And as you can see, it got squatted as of last week.
I'm pretty sure there is another way, though.