Visual Studio 2010 SP1 install hangs, VS2010-KB983509, Warning 1909.Could not create Shortcut

Last week I was upgrading the Visual Studio 2010 on multiple workstations to SP1. On one workstation the update kept running and running for more than an hour and got stuck on installing "VS2010-KB983509" . Cancelling and reapplying the update didn't help. After some googling I tried to remove and reinstall the Microsoft Visual C++ 2010 redist and runtime. This also didn't help. 


After doing some more research I found you can monitor the log file of the SP1 install in %TEMP% folder
look for a file with the following pattern  HFI*.tmp.html and a recent date.


In my case this log file kept growing and growing so I opened it and pretty soon it was obvious that the installer was stuck in a loop trying to create a .lnk file


This was the exact error: "Warning 1909.Could not create Shortcut Visual Studio Itanium Cross Tools Command Prompt (2010).lnk. Verify that the destination folder exists and that you can access it.  Are you sure you want to cancel?"


If you read this error you would expect to see a popup window asking to cancel the install but no popup was displayed. So by doing some more research I decided to look at the %comspec% environment variable. You can do this by running the set command in a cmd window or win + r and run sysdm.cpl and go to the advanced tab and click on the button "Environment Variables" 


The %comspec% variable should like %SystemRoot%\system32\cmd.exe but in my case, some previous installer left /blabla/blaa.bat after the cmd.exe part. So after changing the variable back to %SystemRoot%\system32\cmd.exe the SP1 installer finished his job in about 20 minutes