We lost power briefly last week due to lightning storm. Afterwards I tried to restart the PC (Dell Dimension 4550) and it took several attempts to get it to boot up, but it did. However, after being up and running for a while, it eventually reverts to a BSOD with various messages ("registry cannot load the hive file systemroot\system32\config\software", or "problem has been detected and windows has been shut down to prevent damage to your computer. Process or thread crucial to system operation has unexpectedly exited or been terminated"). Since it will boot up and operate (albeit quite slowly, and only for a limited time), just looking for suggestions as to source of problem or any diagnostics that can be run. Thx.