Inspiron 1545 freezing repeatedly...

Having a bit of an issue with my Inspiron 1545 over the past week.  Just started experiencing multiple freezes with the system for some reason.  Each time it freezes, I have to hit the power button to turn it off, then it starts back up saying it must do a CHKDSK.  Once it completes this, it starts up normally, then freezes again, and the cycle repeats.  It at first seemed as though it was having an issue with TMP files, so I cleared out everything in my Temp directory under Users->Local->Temp.  It even froze when I tried to simply clear out the Recycle Bin.  The freezes start by simply stating that whatever program I'm on is Not Responding.  Then when I try to restart it by clicking the Start button, the Start Menu will stay on screen, then the screen is completely frozen with only my ability to use the touchpad to move the mouse, but I can't click anything.  However, sometimes (like just now) IE8 or Firefox will freeze for about 30 secs, say Not Responding, but then resume...

When I attempted to do a System Restore to a few weeks back, it froze up then as well, and now all of a sudden all of my previous restore points are gone.  I wanted to do a complete system restore to the factory settings, but I can't seem to find out how to do this after hitting F8 or Ctrl+F11 at the Dell splash screen.

Only had the 1545 for a year now, and it originally had Vista on it, but I got the upgrade discs from Dell to upgrade to Win 7.  Can anyone help with this, or at least help me figure out how to restore the entire laptop back to the factory settings to start all over?  *frustrated/worried*