The user who runs the update program must have write permissions in the EMIMS directory structure usually found under ..\Program Files\. They also must be able to change registry settings in HKEY_LOCAL_MACHINE\EMIMS.
If the user can use eMIMS and save changes to preferences, then they should be able to apply the updates. In an out of the box XP installation, the permission level required is that of a Power User.
The update needs to be applied to the eMIMS network image from a workstation that runs eMIMS. The user who runs the update must have read/write/create permissions in the EMIMS subdirectory (and its subfolders) on the file server where the server image is located. They also must be able to change registry settings in HKEY_LOCAL_MACHINE\EMIMS on the workstation computer. As in all server image updates, you need to be sure that eMIMS is not being used by anyone else at the time you are applying the update.