I really like defraggler but had an experience.
I am posting this for general information.
I started a defrag on ?C? but stopped the defrag for a moment to delete the temporary internet files. I then re-analyzed the drive but it failed and gave an error. (I did not write the error down and forgot exactly what was stated, seems like it was just one word) Anyway I decided to reboot. Upon rebooting, the bios saw the harddrive but displayed ?Error Loading Operating System?. I have removable drives so I booted another machine to have a look, Windows Disk Management saw the harddrive but showed that the drive did not have a file system. I then booted from my Windows CD & performed a FIXMBR & FIXBOOT.
This took care of the problem.
I thought about trying to repeat the sequence of events but back out for now, that was quite a scare.