Windows XP/2000 - Disabled Task Manager, Again! posted in the Operating Systems forums; no worries dude
Start -> All Progras -> right click on Startup and select Open...
Note to Rayboto--- googling this issue brings up some questions about spyware/malware disabling your TaskMgr-- you might want to look into this further when you have some time. You may have a 'bug' of some kind.