Rick,
Suggest you look at anti virus software. In Norton, .sct files are part of the list of files scanned by smartscan. Try excluding this.
I too have similar problems on the same platform with one of my clients. Did 2 things, one was in the anti virus program as above, 2nd is the file association. The .sct files were somehow associated with windows script file.
Having done the above 2 steps, the incidence of error has reduced substantially. However yet to completely cure the problem. The PC that still has this problem has MS SQL server installed. I've yet to figure this one out.
HTH
Yau