What to do?  Premiere Pro CS5.5 has quit responding and won't play project.  Windows no recognize

This is jeffaok again.  It seems the files are label unsupported or damaged.  The audio tracks play well but  with the video some play ok and some just play part way through and then stop as I try to play through the sequence.  Should I try to install premiere pro again and what happens to the projects when I do that.

Jeffaok again.  This forum writeup shows up in the program monitor in the Premiere Pro project I am working on!  Weird.  Any suggestions would be appreciated.  I am new at this.  Made a couple of short movies and all went well.  Now trying to make some changes today in one of them and everything seems to be affected and it says it can not find some of the files.  Not sure what I may have done as I have not worked on it for awhile.

John,

Great links on how to ask for help.  Thank you.    I recently installed a PNY quadro 2000 video card.  Have 24 gigs of ram, Areca Raid Card with Raid 5 with four hard drives in Raid 5, i7 920 cpu not overclocked.  Velociraptor C drive.  Everything seemed to be working fine until I returned to this video today and was to burn another copy on encore.  It did not function right and did not burn.  Went to see what was wrong and the whole thing seems to be acting strange.  I ran two virus checkers and nothing was reported.

Any suggestions would be appreciated.    Thank you.

Jeff