Warning: this process will effectively re-route all file pointers from C:\Users\* to another volume. Windows is hard-coded to restore to this C:\Users directory; therefore, converting this folder into a junction will cause problems during system restores
Step 1: restart the computer into Recovery Mode (i.e. pressing F11 on HP laptops)
Step 2: At the system command Window, run these commands:
robocopy C:\Users D:\Users /mir /xj /copyall
ren c:\Users Users_old
dir c:\
d:\Users: mklink c:\Users d:\Users /j
Explanations:
a. D:\users is the new volume to replace C:\Users
b. /mir tells robocopy to mirror the directories, this will copy all files
c. /copyall will copy all the attributes includings ACL and Owner info
d. /xj is to direct robocopy to NOT follow junction points – this is absolutely necessary!
e. Rename C:\users (so that this change can be reverted)
f. Verify that the C:\Users directory has been renamed as a pre-requisite to replacing such object with a junction
g. Create a Junction from C:\Users to D:\Users
h. Exit the recovery console to resume Windows booting