Just moved this thread to the Hardware Forum...

Re: Question - It could be a graphic card issue ? Can you post the entire specs for the new computers ?

My guess is either the "Places" in the open dialogue, or the "Recent Files list" perhaps from the .ini file, are pointing somewhere inaccessible on the LAN, or far away on a WAN? Or is all of the UAC crap turned on in Windows? Ive seen that make Revit drag butt...

I've seen the UAC corrupt the framework and render Revit useless.

As Twiceroadsfool pointed out the User Account Controls should be turned off or turned to the minimum setting. The UAC controls can be found in the User Accounts from the Control Panel. W7 calls it "Change User Account Control Settings" in the user account.

It can cause all sorts of slowdowns with production programs when trying to browse for files. The places can be reset by browsing to the INI file found at C:\Program Files\Autodesk\Revit Architecture 2011\Program on the basic installation called Revit.ini. In there you want to remove the lines after [Recent File List].

Also check your graphics card release date. This can be done by going to the start menu and typing DXDIAG into the search window. The display tab will give pertinent information about your graphics card and it's driver, including the driver release date. If the driver is significantly older it should be updated.

In that same Program folder mentioned earlier you can find a file called Revit.FilePreview.dll. This can cause slowdowns as well if it is corrupted. Simply rename the extension to .old.

To add to what Aaron said, I have seen this happen when IT changes DFS mapping or folder names on the server. Suddenly Revit is impacted, and the user knows they didn't do anything. IT may have even automated fixing all sorts of links and shares and such, but didn't realize that Revit (And Acad) have their own dependencies as well.

Gordon