When upgrading, install.bat "disappears"

System

Trying to upgrade TS6.1 to 6.5. When I click on the install.bat script, I see the DOS window doing its little thing and then the window disappears, with no installation dialogue to follow. I've even tried invoking the "private.exe" command directly but to no avail. I haven't seen this before and I'm wondering if this is a known issue with the 6.5 installation on a Windows 2003 server? I've read the installation guide but it makes no mention of this -- at least, not that I've found.

Thanks,

Dave

Current Environment(s):
(1) TS 6.5 on W2K3
(2) TS 6.1 SP1 on W2K3
By the way, I miss Unix terribly.