Dreamweaver hang not responding

Hi everybody ! 

I am IT support and have a problem with a customer's Dreamweaver software.
For 2 weeks, when my client opens dreamweaver with project, it is very very slow and it stops responding.
when my client opens dreamweaver with project, it is very very slow and it stops responding.
At first I thought it was because of our VPN. I had the client moved directly to the office and
we have the same problem directly with a network cable.
We also did a test on a virtual machine and the problem does not appear and dreamweaver works very fine.
I tested :
- Delete settings from registry and dreamweaver folder in appdata. Many time.
I noticed when I opened that it kept the last directory on the network in memory
even if there were no more settings. Is this normal?

- Delete Temp Files List in registry
- Disable "Display External Files" option
- Create registry key : ResolveRemoteURLToIPAddress with FALSE value.

Do you have other solutions / ideas? If not, I will think about reinstalling Windows from scratch.

thanks you for your help.