I have a MacBook Pro 13 late 2008 for which I just replaced the HD with a WD Blue notebook 500GB, 5400rpm, model WDBABC5000ANC-NRSN. After replacing the HD, powered up the MBP, the screen displayed a flashing folder with ?. I think this is normal since there is no OS loaded. I inserted the Mac OS X Install DVD OS version 10.5.5 which came with MBP and restarted holding down C until a grey screen with apple logo and spinning wheel at bottom appeared. It stayed like this for 2 1/2 hours so I shut down. Any suggestions would be appreciated. Please be detailed as I am a novice user.