4.Only one SID key ending in ".bak"
a) Right-click the SID key that corresponds to the affected user account and click Rename.
b) Remove only .bak from the end of the numbers, and press Enter.
c) In the right pane, right-click the RefCount value (if none exists, right-click the right pane and click New and DWORD (32 bit) Value, then type RefCount and press Enter), and click Modify.
d) Type 0 into the Value Data textbox and click OK.
e) In the right pane, right-click the State value and click Modify.
f) Type 0 into the Value Data textbox and click OK.