UDK Fatal Error during installation -- Running Windows 7

[barbersam]

I cannot get July 2012 UDK Beta to install properly.
At first it said I need XP Service Pack 3 but I read on another page (the link to which I have now lost) that you can bypass the UDK Install .exe searching for SP3 by making a shortcut and adding " -progressonly" to the end of the target.
Now all I get is the logo followed by an error sound and the window has "UnSetup.exe -Fatal error" as the title in task manager.
Have tried redownloading and trying older builds available on the UDK dl page.
My PC should be up to specs...

Windows 7 64x
4 GB RAM
Intel Core i7 CPU 870 @2.93 GHz
NVIDIA GForce GTS 450

[Zeqzy]

Just Click the udk installer not use custom commands udk does work on win 7

[barbersam]

Just Click the udk installer not use custom commands udk does work on win 7

Really? I mean it has "Windows 7 64-bit" under the Recommended for Content Development: heading in PC Specs on the downloads page...?
The " -progressonly" thing was something I found in an old epicgames/udk forum thread when trying to google my problem.

[barbersam]

Still haven't had any luck with this. I have friends who ran UDK on Win7 with no issues, not sure if theirs was 32 or 64 bit.

[geodav]

i use win7 64 bit on various machines without any problems, try installing it to a different partition eg not C:

also make sure you have admin rights on your machine

[barbersam]

i use win7 64 bit on various machines without any problems, try installing it to a different partition eg not C:

also make sure you have admin rights on your machine

Yes I have admin rights and have tried Run as Administrator
When I run the installer I don't get a screen asking me where to install. The logo screen (http://i.imgur.com/xKRU7.jpg) pops up and after a second or two I get an error sound, then the window freezes until I close it by right clicking on the start bar or through Task Manager. The window title in the Task Manager shows UnSetup.exe - Fatal error.

[VendorX]

Which antivirus program you have? If your OS is up to date, then try to disable antivirus - find Run at start up or something similar, restart OS and try again.

[geodav]

you might also need framework .NET 4.0 , think thats what its called, its part of windows 7 so it doesn't cost any thing

[barbersam]

Which antivirus program you have? If your OS is up to date, then try to disable antivirus - find Run at start up or something similar, restart OS and try again.

Tried turning off my anti virus, trying installer again; didn't work. Then turning off run at startup on my antivirus, restarting, running installer again. Still nothing.

you might also need framework .NET 4.0 , think thats what its called, its part of windows 7 so it doesn't cost any thing

I already have . NET framework 4.