I'm trying to check a volume with the standard UI tools (right-click, tools, check now), and this is failing with the error:
windows was unable to complete the disk check
As recommended by a random forum post Google found, I tried to force a check on boot with chkntfs, however no check happened.
How can I check (and attempt repair!) this volume?
Try this, open a command prompt, and type "chkdsk c: /r"
It will tell you the volume is in use, and ask if you would like it done on the next restart. Hit "Y" and do a normal restart.
You can also boot to a PE environment or the Recovery Console and use the chkdsk c: /r command there.