Is this the message you received?
Failed to connect Windows Services, could not find group policy client.
Is this appearing when starting Windows?
If this is keeping you from opening Windows can you boot into Safe Mode.
To enter Safe Mode press the Start button on your computer and immediately start tapping the F8 key and continue till either this boots into the Advanced Boot Options or you receive the Windows Services error message. If you can boot to the Advanced Boot Option use the up or down arrow to move the cursor over Safe Mode and then press Enter.
Please let us if I've understood you post, and let us know what happens.