Try this. Dont be too hopeful but something to experiment:
1) Restart your device.
2) Open "File Explorer"
3) If your not in the root folder ("My Device" folder), select the "My
Device" folder from the drop down menu (below the start button)
4) Open the "Temp" folder
5) Delete all files and folder inside the "Temp" folder
6) Go back to the "My Device" folder then open the "Windows" folder
7) Copy (or backup) the "Activesync" folder to somewhere else (for example
to your storage card)
Open the "Activesync" folder
9) Delete the following files "CtrlLog" and the one that looks like a
registry entry (mine is "{A6E58374-2...", i'm not sure if its the same with
all devices
10) Connect your device to your PC, ActiveSync will do a couple of sync but
it should stop after 3 or 4 times.