If you've access to SW Knowledge Base then please try what has been mentioned under Solution Id: S-058002
Did you ever get an answer to this issue?
I have the same problem only the other way around, windows explorer crashes randomly when the file preview is enabled. Since updated to SW2015, the previews are only showing about 50% of them, very annoying; we have already contacted our VAR but they have no clue and forwarded it to dassault.
The work around right now is to turn previews in windows explorer off