SBS 2003 C:\Windows\Installer too big?

Dear all,

I am running SBS 2003 with all the latest service packs. I have Exchange running on a different partition.

My C: drive is getting full, went looking and found that C:\Windows\Installer is around 14GB of data..most of the files are .msp (Windows Installer Patch) most of them dated 12/11/2007.

First what do these files do? I’m assuming they are client update files..so as the server downloads an update it holds a copy so it can pass down to clients, but not 100% sure.

Second, can these be deleted?