Inaccessible Boot Device after update to HDD controllers

My Dimenson desktop (Win XP Pro / MCE 2005 with 2 SATA HDDs not in RAID config) was bluescreening a lot.  The Microsoft Error Reporting utility informed me that the problem could be fixed by installing updated Intel drivers (I believe for the HDD controller).  I followed instructions, downloaded the indicated file from the Intel website, and installed it.  During the installation it warned me that while I could uninstall it doing so might make my HDD's inaccessible.  After the prompted restart, the computer bluescreened again.  I could only get it started in SafeMode and couldn't recover from there.  I decided to roll back to a Restore Point.  After doing this, the computer continuously bluescreens giving error: 0x0000007B Inaccessible Boot Device.  It doesn't recognize my hard drives.  When I use the Dell Win MCE 2005 recovery CD's Recovery Console I can see the drives and all the files/folders listed and intact.  I believe to recover I may need to restore the original HDD controllers.  Any suggestions on how to recover my system?  Thanks in advance. . .