The day may come when you find that you need to move the package share (SMSPKGC$) to a different drive - say from the C: drive to the D: drive, and you don't want to have to recreate any existing packages or advertisements. Should that day come, Rob Morris wrote up some steps you can follow to get that done:
Note that the permissions outlined above were the permissions in my test environment, so those in your environment may be different. It is also recommended that the D: have more free disk space than C: at all times. Another option would be to place the NO_SMS_ON_DRIVE.SMS file on the C: drive to prevent SMS from placing any components on that drive in the future.
J.C. Hornbeck | Manageability Knowledge Engineer
After doing all the above steps, we will have to update the IIS with the correct path for the SMSPKGC$ virtual directory.Reconfigure IIS to point to the new location:Open IIS=>Default Website, and select the name of the folder.In the right pane, select Basic Settings.If the old location is listed, update to the new location.Change to the new physical locationClick OK, then Restart the Default WebSite