September 2011 Beta + win xp 64bit = no install

[n.a.]

hello everyone (and epic in particular)

although i haven't posted here before, i've been learning+updating UDK since 2010,
when the mail notification for this September's release arrived, i've downloaded it.. tried to install it... unfortunately an error message said that win xp sp3 is required.
this never happened before (the previous Beta build worked fine)

the 64bit version of win xp only received updates untill (and including) service pack 2

will support for win xp 64bit ever return?

[ZeJudge]

A member of my development team is having the same issue, but he's using Windows 7 x64.

If he looks into the Properties of the setup .exe and under Compatibility tab he can't use any of the options there.
This is very odd.

Not sure what the solution can be.