Hi Doctor Leo,
Thanks for your reply. I have an old version of TS2000i Version: (5.00.0512 Date: 03/08/1999) which apparently requires SP3 to be installed prior to being able to install SP4 and SP5. SP3 was large and originally sent out on CD to all the registered owners of the software and was not available for download. SP4 and SP5 can be had from the TradeStation and (old) Omega ftp sites without problem. However, the SP3..... not so easy!!