Notice: The information in this post in out of date because in Windows 8.1, Microsoft has removed support for the transfer cable in their Windows Easy Transfer program. Instead, please use the Bravura Easy Computer Sync program that is included with your purchase of the Plugable Easy Transfer cable. Instructions for doing that are on this page. Thanks!
Microsoft’s Windows Easy Transfer is a fantastic way to quickly import all the stuff that makes your pc yours: music, photos, videos, even personal settings like your desktop background and customizations to fonts, sounds, and other user account settings. Unfortunately, many users find that their old PC doesn’t properly install the driver for the USB Windows Transfer cable, so when they try and launch Windows Easy Transfer, they wind up stuck on the “establishing connection” screen below: 
If Windows Easy Transfer is stuck on the “establishing connection” screen pictured above, or you’re seeing the “Windows Easy Transfer can’t connect to your other computer” error as shown below, and you’re trying to do the transfer over a USB Windows transfer cable, there’s a good chance that manually installing the device driver on your older PC will get you up and running. 
To determine if driver installation is your issue, launch device manager by holding down the Windows key and tapping “R” while holding the Windows Key. In the box that appears, type “devmgmt.msc” without the quotation marks so the entry matches the picture below, then press enter: 
Our first step in troubleshooting WET connection errors is to check device manager for devices with errors as illustrated here: 
If you see a “USB Transfer Cable” under “Other Devices” with the yellow exclamation mark as pictured here, you’ll need to follow the steps below to manually install the driver. Also, please note that either old or new PC may need this fix, however most often the old PC is the one that needs the driver manually installed. To manually install the driver on a Windows 7 system, follow the steps below.
- Right click on the “USB Transfer Cable” under “Other Devices” with the yellow exclamation mark, and choose “Update Driver Software”
Right click and choose “Update Driver Software”
- Select the option pictured here to “Browse my computer for driver software”
- Either copy and paste in the following value or browse to this directory, then click next so the “Update Driver Software” wizard is as pictured below, then click next: C:\Windows\System32\Drivers
- Device manager should report that drivers have been successfully installed, and Windows Easy Transfer should now run normally.
These instructions apply to both Windows 7 and Windows Vista. For Windows XP instructions, take note of the 2nd post on Microsoft’s Answers forum by “Pareeeee”: Pareeee’s post on Microsoft’s Answers forum.
“You’re currently logged on using a temporary profile. Restart you computer and try again.”
This issue has been reported several times on Microsoft’s answers forum, and has been written about by Microsoft MVP Mitch Tulloch at Windows Networking. Thanks to Mitch for his explanation of the issue. I’ve attempted to explain how to complete these steps in more detail below:
To run regedit and do the .bak deletion:
press windows key + R
run window appears, type regedit.exe in the prompt and press enter
click the small triangle next to HKEY_LOCAL_MACHINE\
more options are revealed, click the small triangle next to SOFTWARE
more options are revealed, click the small triangle next to Microsoft
more options are revealed, click the small triangle next to Windows NT
triangle next to CurrentVersion\
triangle next to ProfileList
and look any profiles that end with .bak and delete these.
LSPfix:
Another potential cause of connection issues for WET is having a corrupted winsock file. Note the post by “Dwebb83” in this thread with instructions on how to use LSP fix to replace a corrupted winsock file.