Another BSOD problem

This is Trish again - same machine that y'all helped so much with last week - and now another problem.
As part of my weekly routine, I was trying to do "Disc Cleanup" on my drives ( I have two hard drives) - but it would not work, It got stuck in the 'clean-up' phase at 1%, and after about an hour, I just cancelled out of it.
I then tried the "defrag" option under "Tools" - which I normally do and then schedule a 'check-disk'. Usually the defrag tool says I don't need to defrag the drive, but this time it said I did, so I started it. It got to 55% and then came the BSOD.
Here is the error messages I got:
STOP:
0x000000D1 parentheses 0x00000034m 0x00000002, 0x00000000, 0xF74C6A18 end parentheses
After this was:
IdeChnDR.sys - Address F74C6A18 base at F74C2000, Datestamp 3cb4d2c0

I had to just shut the machine down and restart it - and it did come back up normally. Can anyone help me out with what this means? And what do I do now?

Thank you so much for any help you can give - I really appreciate it!

Trish