I bought "ELSA Microlink 56k USB" modem. Connected USB cable, WIndows recognized it, but right drivers can not be found on CD. On ELSA homepage are the same drivers as on CD that came by. When i browse to path where i extracted drivers, there is driver for "MicroLink 56k USB" but when i confirm, it says that this drivers where not written for this device. What the hell is this. Power light on modem is not lit but i don't if it should be or not. At powering comp. on there is some blinking but thats all. If i install this "false" dirvers there is xclamation mark on it in Device manager and it says that there are not correct drivers installed. I've also one internal modem Rockwell installed and "ELSA Microlink 56k internet". Both working, but these are not mine (only for testing). But i think that this cannot be the cause. What to do?

You provided no system details which makes diagnosis little more than guesswork, but I suspect that you're running a Windows 95 system. Am I right?
USB modems, and indeed many other devices, WILL NOT WORK on Windows 95 and need Windows 98. I know you probably have the USB modification but even so these devices need a minimum of Windows 98.

No, i'm using Win98 SE and i have USB mouse and ext. ZIP drive both working. I have 4 USB slots.

There seems to be a wide variation in the quality of USB driver installation software. Many products specifically require you to install the driver from their own installer rather than let Windows search for the INF file on the installation disk or CD. This may not seem very helpful, but go back and read the installation instructions carefully and check that you have followed everything faithfully. Also, check that there are no problem entries in the System/Device Manager (Control Panel) which might be interfering with the installation (look out for re Xs or yellow exclamation marks.
Ian