have used various cables and custom made adapters, computers and express cards, can not connect to card with express messenger software

you just need a null modem cable.

I lost my Express Messenger Disk to connect to the system, do you know where I can get one...
Thanks so much

Not sure what you are trying to do but you can do just about everything from a SLT if you are in a pinch

You said you have tried all cables but if this is a system in a hotel that is interfaced you first need to dial into the system by phone and from the administrators mailbox set the port to program (or serial - whatever) from interface before you can talk to it via computer.

What Version of Windows r u using?