As I'm only interested in using ZCM with my Windows 7 migration early
next year (currently running ZfD4 against W2K clients), I was excited to
hear that 10.2.1 was allowing for Windows 7 RTM registrations to ZCM
(yes I know it's not supported but was added to assist in testing).

Applied the 10.2.1 update to my single ZCM 10.2 server with any issues.
Manually installed 10.2.1 client to Win7Pro workstation. Rebooted
everything and had my Windows 7 Professional test client try to
register. Still get the same old...

Service Error. code: -21 message:
Could not determine device type from
<OS> tag: unsupported

That's odd. I thought 10.2.1 included the modification to allow for
Windows build 7600.

Checking the zmd-message.log file it shows my entire OS string is...

"Windows 7 Professional (Build 7600)"

In the work/cache/registration/ostargets.xml file I see an entry for
Windows 7, which seems right.

Has anyone gotten a Windows 7 RTM to correctly register to ZCM 10.2.1?
If so, what version of 7 was it? Is there some kind of cache on the
server side I can clear to possibly help?