Modem not detected

Delete old driver files and re-install current version.
Troubleshooting the MT5634ZBA-USB and MT5634MU [For Windows 95c, 98, 98SE and Me]
Generally when there is a problem with a USB device it is due to incompatible driver files. This can happen when the firmware is upgraded, but the drivers are not. This is a procedure designed to start an install from scratch after encountering a problem.
1) Physically disconnect the USB modem
2) Use Windows Explorer to open the Windows\INF\Other folder*
3) Delete any of these drivers: Moore Computer Consultants Inc, ATLASVX.inf, ATLASWD.inf, MTSUSB.inf, MDMMTUSB.inf
4) Do a Find or Search of the main drive (usually c:\) for "MCCI" (without the quotes).
5) DELETE all files containing MCCI in their name. There are nine of them:
MCCICM95.SYS MCCIMNT.SYS MCCICOMM.VXD MCCICR.SYS MCCIMDM.SYS MCCIVCD.VXD MCCIW16.DLL MCCIW32.DLL VMCCICR.VXD
6) Reconnect the USB modem and use the most current drivers from the Website (http://www.multitech.com/drivers.go)
7) If this fails to fix the problem, go to Device Manager and expand the Universal Serial Bus section at the bottom and DELETE the ROOT HUB. Re-boot the computer and Windows should find new hardware: USB. Now try installing the USB modem (make sure the above MCCI files are not already present).
* This may be a hidden folder. To be able to see it, open Windows Explorer, click on the View drop-down menu (Tools for Windows Me) and select Folder Options. Next select the View tab and select the Show All Files radio button (Show hidden files and folders in Me) and click OK.