Try this on the Windows 7 system and see if it helps.
You'll need to use the registry editor and go here
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
On the right side double click LargeSystemCache and change the value from 0 to 1
And then here
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters
On the right side double click Size and change the value from 1 to 3
Reboot your machine and see if the problem is resolved.
Using the Windows Registry Editor can cause serious, system-wide problems that may require you to re-install Windows to correct them. It cannot be guaranteed that any problems resulting from the use of the Windows Registry Editor can be solved. If you choose to edit the Windows Registry please understand that you do so at your own risk so unless you feel fairly comfortable and confident you should probably not use the Editor. Changes made to the Windows Registry can take effect immediately and those that do not will take effect following the next reboot of your computer, and a current backup is not automatically made for you....So manually create a system restore point, backup the registry and export the key you are editing for safe keeping before doing so.