um, uninstall ms.
then reinstall it.
put in reg key
wait for atleast 4 minutes(then your sure). let the program just run.
then close down the program and restart it.
and you can wait for 30 minutes but the program wont do anything. it recognize the reg key after a few minutes and then it need to be restarted, BUT DONT TOUCH ANY BUTTON IN THE PROGRAM. after you have registered and have to wait for atleast 2 minutes. if this dont work,then i dont know it.
oh and for the people who think: how does he know. read a faq on their forums, they explain it all. so next time take your time to search. i can understand they wont reply to your posts.
and some other modelers, you cant use this for hl but there fun
www.wings3d.com
www.anim8tor.com
thats my real beginning in august last year.
and offcourse the good ol powerfull blender 3d
www.blender3d.com
it is as powerfull as 3dstudiomax but its tricky and you need to be used to a overfilled interface and have a good understanding of 3d modeling to use this program well.
this should help you out for a while.