This is the problem:
Open Writer
Click File->Open
Writer “freeze” and you have to stop the application from task manager.
The folder that cause the block is “Desktop”. Opening a different folder, the problem does not occur.
Libreoffice v. 4.3.0 Windows 7 pro.
If this did not happen right from the first usage after installation a solution could be to renew your user profile. For information please refer to: https://wiki.documentfoundation.org/UserProfile
Should this not lead to a solution, I would write a bug report, which can be done here: https://www.libreoffice.org/get-help/bug/
and explain all details.