I have some problem with the .net runtime since installing some recent sharepoint fixes but as I can't see anyone else having had this problem I think it may be coincidental and the runtime just needs repairing.
So, I do the usual thing, open Add/Remove Programs find Microsoft .NET framework 2.0 Service Pack 2 and click on "Click here for support information" whereupon I get the version information and a Repair button. Clicking on Repair asks for the whereabouts of "netfx20a_x86.msi" which I don't have on my system, so I can't repair it.
I download the .Net 2.0 SP2 distributable installer executable from Microsoft, use the /T command line to open it up so that I can see the files and sure enough there is the netfx20a_x86.msi installer a few directories in. So I go back to my Repair option and provide the path to the msi file.
After a brief moment i get an alert box saying "to install this product please run setup.exe" which is nice, but I don't want to install it. Still, I make the effort and go back to run setup.exe.
I get a message informing me that this product is already installed on this machine and if I want to repair it I need to use the "Repair" option from Add/Remove Programs.