Today I installed a Windows Server 2008 x64 VM to use as vCenter 4 server. Everything went fine until the DSN option gave me the (Please create a 32 bit system DSN) message.
I created the DSN via: Start – Run – msodbcad32. The weird thing I noticed was the small amount of options available, only two as you can see in the picture below.
To solve this issue, start Odbcad32.exe from the following location %systemdrive%\Windows\SysWoW64\Odbcad32.exe instead of Start –Run – Odbcad32.
Now we have the options we need:
Create a new system DSN for vCenter and vCenter Update Manager. Start the vCenter installer and select the right DSN:
More information about this issue can be found in: KB942976