DavePurscellI know this is an old thread, but thought I would add it. When considering a defrag, I recommend using Contig from SysInternals. Granted it is only a file level defrag tool, but it does a very nice job -- much nicer then a native Microsoft defrag.
On a new machine, I run it nightly for a few nights. By that time you can drop back to running it weekly to keep things clean.
LmhansenI do have something similar, but I cannot share this one (sorry, I can't give everything away.)
Two comments on this, though:
1) It's not generally recommended to defrag a drive if there is less than 15% of free space available. There simply wouldn't be enough space to move large files around to make the necessary space to keep everything together.
2) defragmenting a drive doesn't recover any space.
Use one of the included monitors to keep taps on freespace on the C: drive.
Set the monitor to run a CCleaner script (or something similar) to free up space. Have this script execute another script to check how much disk space is available (this is the tricky part. I solved this with a VBScript. Have this script write an event log entry if there is still less than 10% free space on the drive.