I am stuck in the middle of nowhere for about 6 more months and there is no high speed internet available. So I am stuck using an old computer and good ole dialup. But I've got a problem. I have been having trouble with a new modem I put in my computer. It has to do with the ports.

MY MODEM - Diamond SM56LE-SL SupraMax 56k Internal modem
MY COMPUTER - Hp Pavilion 511n - Windows XP (no service packs)

This new modem was working fine in the computer for a few months. The other day I could not get a connection. The error I get is that the port is being used by something else. I am positive there is nothing else using that port. I have tried many different troubleshooting ideas but nothing has worked. I had not changed anything on the computer or added new hardware. I was using the modem earlier that day and logged off and about 2 hours later I went to connect and couldn’t.

I have come across 2 different problems that may or may not have anything to do with it but I am not sure and would not know how to fix it if one of them was indeed the problem.

1 - While I was trying a possible fix (that I got at HP support website) I was in the BIOS and was checking the base I/O address on port A & port B. But I only seem to have port A, no other port shows in the BIOS or in the device mgr. Should'nt I have 4 COM ports?

2- I tried to update the BIOS and I got the error message - Can't find the system bios hook. I don’t know if updating the BIOS would solve the problem but until I get around this I would not know.

I have done alot of the obvious troubleshooting like rebooting, updating the drivers, putting the modem on a different port, putting it in a different PCI slot, etc. I have my old modem and I stick it in the same PCI slot and it connects without a port problem (I just have to dial with my home phone and help it along and its real slow)

But I do know that the modem is compatible with my computer because I had been using it for several months.

You could have gotten malware/spyware/trojan dialer that is using the modem/port.
Run a program like Lavasoft AdAware, Spybot, etc. to see if anything comes up;
Check the task manager for running processes: CTRL+ALT+DEL - processes tab - use google to identify what the processes are for;

Some software can cause wierd/unusual conflicts - including Quicken, Quickbooks, many Symantec problems including Winfax, and Norton-branded products

Boot computer in safe modem with networking and see if modem works;
You might try putting the modem in a different PCI slot;