Win7 pauses Boot after post for 2 Minutes

Hello, we see a weird behaviour after restoring files from Backup to a folder.

We are about upgrading the Computers to Win7.

The Process is:
Make an Image from the client with Acronis 11.0.17440 to external USB HDD.
Clean Harddisk
Install win7.
Up to then all is fine, the system boots after Post (Windows is loading) without delay.

Then we restore the Files from the Image on USB HDD to a local Folder c:\OldData via Boot CD.
This sometimes takes 7 Hours for about ~ 60GB.

After this the System has a delay of ~ 2 Minutes after post, until 'Windows is Loading' appears.

This behaviour also persists if we delete this folder, restore without acl's and so on, so it is
unreversible.

What does acronis do to the hdd in this case ?

How to Fix this ?

Br
Thomas