Shutdown, Restart problem

Hello, i'm fairly new to the mac scene, i've always been a windows person but i've switched over to mac. as you can see i have a mac-book pro and my problem is i cannot restart or shut it down. when i do it looks like its going to shut down or restart but all it does is becomes a blue screen and then my desktop pops right back up. the only way to turn it off now is to hold on to the power button but i don't feel right holding it down. and this happens also when i click on About this Mac on the apple context menu. i've tried to reformat the macbook with a new Tiger OSX cd but for some reason when i try to re-install it it says MAC OSX 10.4 cannot be installed on this machine. i've researched around but i havent been able to find a solution. i hope someone can help me. thank you in advance.

try this

shut it off with the power button, do a reset on the pmu and then a pram reset and see if it fixes the problem.

as for reformatting, you will need the restore cds the macbook pro came with. the retail ones are not made for intel base mac. hope this helps.

hmm i just tried those two things, it didnt work. =\, an update on what's happened is i just got the latest updates on the mac and when i finished installing it, it asked me to restart or shutdown so i hit restart. and amazingly yet it did restart without problem. now after that i tried restarting it myself with the restart button but it didnt work. this is so confusing. oh yea i can't even get into my "About This Mac" info to work either, i'd click on "About this Mac" and then click "More Info" and the mac would go into the blue screen and go back to desktop.

hmm it's been a while now, still no solutions.