Software-Based Modem Problems on Win2000 WinXP Systems

Hi All,

A call to any techs who can help. I work for a large company who has thousands of clients with Dell PCs. We have a product that uses a dial-up modem to access timeclocks. We never had problems with Dell PCs until Windows2000 and WindowsXP came out. Our software no longer initializes the modem or dials out when using software-based modems under those OSes on Dell PCs. Conexant, HSP, HCF, WinModems, what have you. USR Robotics modems, or most any external modems, no problems. But any and every generic or SoftK modem, and we're sunk. Now the conexant-type modems have no problems with hyperterminal, phone dialer, or most dial-up programs, as far as at least dialing out but not with our software, and I've heard some other programs have the sane problem. Now my question is this: How does Win2000 and WinXP differently address those software-based modems than the modems with all their chips intact? I can rewrite (or assist with rewriting!) our software, but have yet to discover what's different in the OS environment modem-wise. Can anyone shed light on this? I know it's not Dell-only as far as these modems go, but Dell is the most popular PC as far as my clients go, and they'd like to stay with Dell, and these generic software modems are now the Dell-default.

Many thanks for any assist

Montag