I have been working on this issue for over a week now. I have searched the net until my eyes glazed over. I finally decided to cough up the cash to give this ago. Unfortunately, it appears that while this topic has been addressed a number of times, there is no silver bullet. Nonetheless, I paid for a month, so here we go.
I purchased a Dell Dimension 2400 for my brother-in-law's family as a Christmas gift last year. About a week ago, his modem stopped working. A few days later a buddy of mine called me asking for advice about his "top of the line" Dell as well (a year old). His modem stopped working as well (COM Port Conflict, Modem in use, etc.). I have only had a chance to tear into my brother-in-law's machine. It has a Conexant/Asus SmartHSFi V92 56K PCI Modem. I am unsure of the Motherboard model, if you can point me to a nice freeware utility that would allow me to look it up, I will get that information for you as well. If I try to query the modem in the diagnostics tab for the device manager I get the same "COM Port not available. There may be a hardware conflict..." message.
Here are the things I have tried (over and over again in various orders):
1) Changed around the COM ports the modem was using
2) Uninstalled and reinstalled modem
3) Uninstalled and reinstalled modem and COM ports
4) Switched the Modem around in different PCI slots reinstalling the modem each time.
5) Bought a brand new modem, installed it. Continued to receive the same error messages.
6) "Rolled back the system, drivers, etc."
7) Ran a Windows Repair on the system with the Windows Install CD
8) Updated all drivers
9) Experimented with various drivers
10) Updated the BIOS to most recent version (i.e. "A05")
11) Ran all of the Windows Update functions through Win XP SP2 and then installed the modem
12) Used CTRL-ALT-DEL to terminate every possible program to determine if some software had obtained access to the COM port
13) Finally did the ultimate. Booted form the installation CD, deleted the system partition, created a new system partition so as to format the whole thing and wipe everything clean. Installed a fresh copy of Win XP with absolutely no other software installed. Installed the modem with the drivers that came with the computer when it was shipped one year ago (and worked).
14) Repeated step 13, but this time installed the brand new modem. Same @#%#@!% error!!!!!
This is killing me! The only thing left that I can think of, is replace the motherboard ... unless you can help.
And, call me suspicious, but it seems very fishy to me to be running into this error on not one, but two PCs at relatively the same time frame and both are Dell machines. Furthermore, it seems as though Microsoft sure has a fair number of knowledge base articles on this topic making me wonder if there really is something other than a motherboard issue here. Anyway, all conspiracy theories aside, can any of you provide me something that would allow me to put this behind me?