How to run chkdsk on boot volume?

HI all.

I have some sort of corruption on my hard drive, and the research I've done says to run chkdsk.

(Well, I get a pop up saying that c:\DELL is corrupt and to run chkdsk.  If I run chkdsk, it confirms that there's a corrupt record associated with that subdirectory.  Here's the output: 

C:\Windows\system32>chkdsk c:
The type of the file system is NTFS.
Volume label is OS.

WARNING!  F parameter not specified.
Running CHKDSK in read-only mode.

CHKDSK is verifying files (stage 1 of 3)...
  234112 file records processed.
File verification completed.
  391 large file records processed.
  0 bad file records processed.
  2 EA records processed.
  44 reparse records processed.
CHKDSK is verifying indexes (stage 2 of 3)...
14 percent complete. (58584 of 849830 index entries processed)
Error detected in index $I30 for file 37344.
Error detected in index $I30 for file 37344.
  849830 index entries processed.
Index verification completed.

Errors found.  CHKDSK cannot continue in read-only mode.

). 

I have Windows Vista, a Dell XPS M1710, and I also have one of those extra D: drives with what looks like a back up of the OS files, if that helps.

How do I fix this?

Chkdsk won't let me fix C: because it's the boot volume and it has to be unmounted first.

I think I need to boot off some other volume, but I'm not sure exactly how to do that.  I don't have a floppy drive.  I can make a boot CD (and I have a System Rescue made already).  I can keep looking but I felt I could make some progress by asking folks here too.

I've already made a back up of important personal data (well, all personal data) to an external drive, so I'm good to go there.

Any help is much appreciated.