I don't know if this fix will work for everyone, but I sure hope it does because it'll make you pull your hair out if you can't figure it out. This fix should work for SBS Essentials 2011 and WHS 2011. They are both about the same and considering the logs on here are from SBS Essentials 2011 and it worked, it should also work on WHS 2011
The main problem with this was caused by the security permissions for task scheduler being corrupted. If you see these lines at the bottom of yourclientdeploy.log:
" 110802.131926.8092: ClientSetup: Running MSI: C:\WINDOWS\Temp\Client Deployment Files\ClientCoreX86.msi SOFTWARE_NAME="Windows Small Business Server 2011" REBOOT=ReallySuppress
 110802.132447.3678: ClientSetup: Running MSI threw an exception:Microsoft.Deployment.WindowsInstaller.InstallerException: Fatal error during installation.
at Microsoft.Deployment.WindowsInstaller.Installer.CheckInstallResult(UInt32 ret)
at Microsoft.WindowsServerSolutions.ClientSetup.ClientDeploy.Helper.RunMsi(String msiPathOrProductCode, String logFilePath, Dictionary`2 msiProperties, Boolean install, ProgressChangedEventHandler progressHandler)
 110802.132447.3678: ClientSetup: RunMsi returned error: RetCode=1603
 110802.132447.3678: ClientSetup: Failed to install C:\WINDOWS\Temp\Client Deployment Files\ClientCoreX86.msi
 110802.132447.3678: ClientSetup: Exting InstallSoftwareTask.Run
 110802.132447.3678: ClientSetup: Task with Id=ClientDeploy.InstallSoftware has TaskStatus=Failed
 110802.132447.3678: ClientSetup: Task with Id=ClientDeploy.InstallSoftware has RebootStatus=NoReboot
 110802.132447.3678: ClientSetup: Exting ConnectorWizardForm.RunTasks
 110802.132503.2127: ClientSetup: Back from the Client Deployment Wizard
 110802.132503.2127: ClientSetup: Saving Wizard Data
 110802.132503.2284: ClientSetup: End of ClientDeploy: ErrorCode=1603"
This is what prevented Launchpad from installing. None of the other errors I posted on here were related to the problem as they were still present in the logs after I had a successful install of Launchpad.
To fix this do the following.
First you need to see if task scheduler is running properly. Use this link provided bysbs_sdet_w to set it up if you don't know how http://support.microsoft.com/kb/308569
Just pick any old task to run. I used disk cleanup and set it to run once. When you run it if you get the error"Task Scheduler error,0x80090016,Keyset does not exist" you just do this next.
- Stop the Task Scheduler Service (run => services.msc)
- Delete or Move ( I created a new folder and dumped them in there) the file(s) from the
"C:Documents and Settings\All Users\Application Data\Microsoft\Crypto\RSA-S-1-5-18" folder.
- Start the Task Scheduler Service.
- Edit each previously scheduled task and provide security credentials( It'll as you for your login) for the task to run under.
- Right click a task and choose run.
The task should run correctly and it should also run as scheduled.
If task scheduler works you should be able to reinstall Launchpad with no problems now. If you haven't cleaned out your old installation of Launched do it before you reinstall.
If you haven't done that before do the following.
1. Remove the clients computer from the Server and restart it.
2. On the clients computer itself, go to Control Panel- System- Computer Name and clickChange.
3. On this tab change the computers name to anything you want to name it as long as it's different from the one that is already there.
4. Change Domain to Workgroup and use the name of the Workgroup you belonged to before. If not, just putAnything.
5. Click OK, You're Login screen should appear, Type in your login for the computer and then follow the on screen instructions to finish.
6. After the computer finishes rebooting run a good cleaner likeCCleaner. Run the file cleaner and the registry cleaner. This gets enough of
the old files out to reinstall Launchpad.
After that, reinstall the Launchpad software and you should be good to go. I didn't have to uninstall .net 4.0 or turn off my antivirus software. But if you don't want to take any chances of it screwing up again, shut off anything running in the background just to be sure.
This is all I did and it worked well for me. Some of your experiences may be different. If I missed anything please feel free to post here and correct it. If you are having this problem, I hope this works for you.