I came across this problem having upgraded a site from 2009 to 2010. It is however a common problem that can occur with 2003 Servers.

Having installed 2010 I went to login into System administration, to update the databases etc.

However as soon as I clicked the icon I got the following error:

Error when trying to access Syatem Administration

Having clicked ok (Twice!!), the console form opens but without any System Administration options.

Solution:

Click ok (Twice)

Select File>Options>Disk Clean Up

Select Delete Files

If you attempt to log in to System Administration at this point the MMC console form displays with the following message:

System Administration MMC error

N.B. This is an error that can occur as a separate issue.

Run the following command prompt:

Cd c:\windows\microsoft.net\framework\v2.0.50727

< PRESS ENTER>

Installutil “c:\Program Files\Sage\Sage200\Sage.MMSAdmin.MMCSnapIn.dll”

You should now be able to access System Administration.