You will need XP Mode for Windows 7
Download and install from the Microsoft site.
This installs a virtual version of Windows XP mode onto your Windows 7.
When you run the program you will have XP in its own window.
This is very useful to run older software's, scanners etc.
Installing modem (2 tips to choose from):
A modem installed in Windows 7 can be accessed in XP Mode by first adjusting the com port settings for XP Mode. This is done through the Settings dialog box , which can be found by either opening Windows Virtual PC (not XP Mode itself), selecting Windows XP Mode.vmcx, and clicking on Settings on the menu bar near the top of the screen or, when XP Mode is running, clicking on the resize button to take XP Mode out of full -screen mode, upon which a menu bar that includes a Tools drop-down menu, on which the Settings option can be found.
Within settings, select COM2 (or whatever port is listed as the physical serial portùI donÆt know if itÆs possible for that to be other than COM2), and set the physical serial port to COM3 (or whichever com port your modem is attached to in Windows 7). Also, check the box that says ôWait for modem command to open port.ö Now go into XP Mode control panel and add the modem. My experience is that the applet will not be able to automatically detect the modem, so you will need to select it manually. From the list offered by Windows XP Mode, simply select the standard modem of the correct speed, e.g ., 56 K, and complete the process of adding the modem. You should now be to select the modem in your fax or other modem-using program. Note that the modem will appear in XP Mode as being attached to COM2, not its actual port in Windows 7.
To get your physical modem recognized in XP mode you don't need to install any drivers in XP Mode.
XP Mode will use Windows 7 drivers.
To attach the modem to the correct COM port in XP Mode, you need to get into the Settings menu for the Windows Virtual PC (not XP mode itself) by either starting the Virtual PC without starting XP Mode or when in XP Mode, exiting the full screen view by clicking on the two squares in the upper right-hand corner of the screen (the familiar restore button between close and minimize--X and -). There you will find a menu bar with a "Tools" drop-down menu. The choices are "Disable Integration Features" and "Settings." Click on "Settings," of course.
When you open "Settings," you will find a window on the left with a list of devices, hard drives, COM ports, and a few others. One of them, presumably COM2, will be listed as a physical serial port. Select that one to modify. Then select the physical serial port option for that COM port in the window that appears on the right half of the Virtual PC screen, next select from the drop-down list the COM port your modem is actually using in Windows 7, and lastly check the box that says "Wait for modem command to open port." Click OK and exit the Settings dialog box by clicking OK.
Go to "Phone and modem Options" in Control Panel in XP Mode and install the standard modem (that is, the generic modem) for the correct speed (matching the speed of your actual modem) and be sure it is assigned to COM2 (or whichever COM port was listed as the physical serial port in the Virtual PC Settings). Be sure that you have uninstalled any modem you may have previously attempted to install before you do this, otherwise the failed installation may block or interfere with installing the standard modem. At this point, you can install (or configure) your fax or other software requiring a modem in the same manner you would if it were running in a physical machine running Windows XP, remembering that you will be using the standard modem attached to the physical-serial-port COM port (probably COM2). This, of course, may also require restarts of XP Mode.