Vista Computer Stalling during Chkdsk

I am attempting to help a friend with her computer. Computer has started
being very slow to start up between welcome screen and actual desktop
appearing.

I have deleted temp internet files, cookies, etc. and ran malware and virus
scans and am now trying to run chkdsk. I checked for it to automatically fix
file system errors and to scan for and attempt recovery of bad sectors. It
appears to be stalled during stage 5 (verifying free space). It shows
112654681 to be checked and it is has been stuck at 9123650 for about 30
minutes now. What could this mean? Do I need to just leave it be, or how
do I stop it at this point?

Thanks in advance for any help provided.