Started with XP SP3 running NIS2008 with no problems.
Uninstalled NIS2008.
Installed NIS2009 from the CD, it would hang on the "10 seconds remaining" screen.
Could not boot into XP.
Managed to get into safe mode and run the Norton Removal Tool.
Could then boot into XP.
Tried to install again. Same hang on the 10 seconds remaining...
Safe mode again, NRT...
Then I removed every symantec/norton directory that NRT didnt remove.
Regedit and delete everything that NRT didnt remove.
Install yet again... It installs, services start, app starts. Then it hangs. Yes, I mean it hangs (nothing for over an hour).
XP doesnt load...
Back to the safe mode/NRT circus.
Spent a pointless 2+ hours with Symantec Instant Online Chat repeating everything again a few times.
Final attempt, NIS2009 installed, loaded, started a liveupdate, installed 4 of 10 and then hangs forever.
XP wont boot.
Support insisted that nobody there has heard of problems with NIS2009.
Current situation = NIS2009 appears to be beta based on the install problems people keep reporting here.