The action of doing a scan also means it is also reading almost every file on your disk(s).
If any file has a fault in a way that the Windows file handler cannot deal with, then you are likely to get a process hang. The fact it happens in exactly the same place each time means its almost certainly a corrupt file which is causing the problem.
I suggest you run the Windows disk "Error Checker" by opening Windows explorer and right clicking a hard drive, then left click "Properties"
then Click "Tools" then click the button which says "Check Now" next to Error Checking. Do this for each disk on your system.