Mount the ISO and open admin CMD... Code: dism.exe /online /enable-feature /featurename:NetFX3 /Source:X:\sources\sxs where X is the letter of the drive. Enabled it offline in mounted WIM with no problems.
So it was my fault. Win 8 x64, I was able to use a 4GB USB drive. Win 8.1 x64 4GB is too small. Thanks James.
I'm not sure if this has been brought up before, but I am using the Windows 8 disc to go from 8.1 preview to save settings, personal files and apps. After this, I will upgrade to the RTM of 8.1. I am just upgrading from the preview back to Windows 8. Just thought I would give everyone a heads up so those that don't want to reinstall everything can do this!
It does work. this is the command Elevated Command prompt. Change source:X change the X to the drive where you have the ISO mounted or your install media drive letter. Dism.exe /online /enable-feature /featurename:NetFX3 /All /Source:X:\sources\sxs /LimitAccess Further Info can be found here support.microsoft.com/kb/2785188
I used a 4GB drive for 8.1 Pro, I think... *looks at USB drive sticking out of the PC* Yes, I put the ISO's contents on a 4GB drive and installed it without any problem!
It did not work win+d or rebooting. It could be caused because I turned off secure boot a while ago and was to lazy to turn it back on, so maybe since the "secure boot is not configured correctly" watermark is there it shows the windows 8.1 9600 mark as well. I will try to turn on secure boot and see. EDIT: Turning on secure boot got rid of all watermark. BUT now I got a new bug. I feel its because I did not wipe computer before updating from win 8.1 preview to 9471 to 9477 to RTM 9600. The bug is every time I reboot my computer, the start screen goes to a black solid background. I always have to change it back to what I normally have.
I'm pretty sure I downloaded and installed x64, I'l check it again, but I'l be really surprised if I installed x86 by accident
I guess my 4GB drive sux I can fit 8.1 x86 & 8.1 enterprise x64 on it though. Didn't like the 8.1 x64. Finally got it activate too via the phone process!!
Maybe 4GBs is not the same for USB drives. I have 10MBs left on my x64 Win 8.1 4GB USB drive. (didn't even realize till just now.)