There are 3 working patches for MWA GUI on Windows Machine.
Patch # 12574324 for 11i
Patch # 12780257 for 11i
Patch # 20983924 for R12
All these patches works on Windows 7 & 8 and with all Java versions.
The first two patches for 11i work on R12 also but with a minor issue. When you press tab even though visually the cursor moves to the next field but in actuality it remains in the previous filed and what you enter is taken as a feed in the previous field. The replacement for Tab in the first two patches is <ENTER>.
To solve this issue the 3rd patch was created which is the latest working patch for R12 also but this patch after some RUP and Patch applications (For other modules) stops working and gives "Connect Failed" error. The first two patches can be used s a solution until a new patch comes as replacement for 20983924.
Please note that the CMD/Batch files for all three patches is made differently so follow the guideline strictly for the respective patch.