Display problem after webserver (IIS) migration

Hello everyone,

I am experiencing problem in displaying correctly my wordpress 3.9.1 hosted on a IIS 7.5 (Windows server 2008 R2 SP1)

I recently had to change the virtual machine (Windows Server 2K8 R2 SP1 for another one, strictly same config.) and apparently had no problem in dealing with migration (export import of Database and everything OK in configuration)

My website is up (www.keepintouchwithus.com) BUT I realized that I now get several display problems…
Examples:
1. on the wp-login.php, the login button is displayed without any style (basic button)
2.when I am logged in as administrator, and I open website in a new Tab, I should get back office tool bar in the upper part of the window. Instead of that, I get the tool bar at the bottom left of my website in a column and I have to scroll down to see it.

I thought it could be css problem but it seems it is related to my imported database. i discovered that because I just installed a brand new parallel wordpresss sinstallation from scratch and this one is displaying perfectly. As soon as I try to import my database (even if I try to import only the eleven initial tables from my dump), the display problem comes back.

You can see what I am experiencing on the following link with printscreens:
https://www.dropbox.com/sh/s3sg5vp4sng3y3n/AAClAKLoDd51Co1ykZAspRH4a/Troubleshooting

Any idea where I should investigate further ?
I am convinced it comes directly from the dump I am using which was exported from a different virtual machine but I just can’t figure out what can be misinterpreted from either the mySQL Server (I am using MySQL server 5.6.17) or the webserver

Thanks for your inputs and a very nice week end to everyone.

Loïc