Re-Installing The CRM Laptop Client for Outlook When You Join A New Domain

Consider this scenario: You have a laptop with the CRM laptop client for Outlook installed and working and the user and his machine have to join a new domain where CRM has been re-deployed.

A crucial step to make this transition go smoothly is to first uninstall the CRM laptop client before removing the machine from the old domain since after you remove the computer from the domain, you will no longer be able to log on with that user's domain profile. If you overlook this step, once the computer is joined to the new domain and the user logs on (creating a new profile) the only way to cleanly uninstall the laptop client would be to join back to the old domain.

But what if the old domain is not available at the time? If you try to install the laptop client under the new user profile, you will get the dreaded error indicating that a previous installation exists - and you can't have two laptop clients installed on the same machine (this is not the case with the desktop client fortunately).

The place to start in order to remedy this would be to follow the instuctions Microsoft has provided to manually remove the laptop client. After following these instructions, you will still get the error when trying to install, but here's the workaround I found:

Essentially the installation routine is checking the registry to see if the client is already in place on the machine. In order to fool the routine, you simply need to remove the relevant registry keys (WARNING: Do this at your own risk. You may blow up your computer if you edit the registry incorrectly.) The problem with the CRM laptop client however is that there will be about 10,000 registry entries for CRM and you'd be better off re-building your system from scratch.

So the trick is to start the install and take note of the error message. It will tell you that there is a previously installed laptop client for CRM with a version number, something like 3.0.5300.1361. Now you can search your registry in the HKey Local Machine node for the string 5300.1361. Deleting all the keys where this value is stored (there should be fewer than 20) will fool the installer and let you proceed with the laptop client installation.

But remember this warning: This is totally unsupported, dangerous, and only a fool (or someone who doesn't have time to re-build their laptop) would attempt it. Happy hacking!