SITUATION: Repair install on Windows XP. Must activate. Can't activate... get black screen.
01.1. Turn On your PC.
02.2. Press F8 repeatedly and go to SAFE MODE WITH COMMAND PROMPT.
03.3. Click RESOLVE LATER (a black screen with show).
04.4. Type: cd \windows\system32
05.5. Type: rundll32.exe syssetup,SetupOobeBnk
06.(one space after "rundll32.exe" - Oo are two letter o's - capitals and comma are necessary)
07.6. Wait a couple of seconds (although you will Not see any change).
08.7. type: shutdown -r -t 3
09.8. You are now able to go to Normal Mode again (For another 30 days !!!).