Installation & Licensing

[#1]

I just installed my autocad2012, and when I went to use it it won't load.  It says it is loading, but it has been 4 hrs. I checked my windows and I have xp sp3.  can someone please give me another idea thank you.

[#2]

Please check if any other application blocked the startup,such as anti-virus,and also try to run in diagnostic mode:http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=6453117&linkID=9240617.