Go to the Control Panel, click the System applet. (alternative to this is to hit the windows keyboard key and the Pause/Break key). Click on the modem icon. Click your modem icons under the modem icon, then click Properties, click the Driver tab, then Drive File Details. This should give you the name and location of the drivers, which you can backup, just by locating the file in the specified folder.
You can then copy it to whatever media you plan to back it up to.
While your under the Control Panel, and the System Properties, be sure to check out the ports, COM applet, expanded it to Com1, Com2, click each one and go to the propeties, Port Settings, and adjust the Bits Per Second to their highest settings. Such as 921600, or on some modems its just 115000. Most common settings for the modem are 8 data bits, Parity None, Stop Bits 1, Flow Control Xon/Xoff, which is usually written out as 8,None,1,Xon/Xoff
Also under the Com Ports, Properties click the advanced tab, and slide BOTH sliders to their maximum settings.
Change the settings for each Com Port, this is the communication port your modem will use. This may be all you need to adjust - unless it is already set this way, then you will want to update the modems driver. But check these settings first. if they are not as described, change them, test it out, if things are OK, dont update driver, if things do not improve or are already set this way, then update the driver.