My computer does not recognize my installed printer as a scanner.

Normally, input devices cannot be shared, at all, but this isn't always true of scanners.  You'll be able to share the scanner only if it's manufacturer provided specialized software for that purpose.

    You have to use a network-capable scanner (which immediately eliminates most, if not all, USB scanners) and specialized software (that comes with the scanner) to do this.  If you're talking about a home consumer grade flatbed USB or parallel port scanner, you very probably can't.

    HP, Canon, Xerox, Océ, Kyocera Mita, and other companies manufacture network capable scanners (They're actually multi-function devices that also copy, print, and sometimes fax and email) and the requisite specialized software.  The cost of such devices usually starts somewhere just below $4,000.00 USD.

    The HP PrecisionScan Pro application, versions 2.03 and higher, which normally comes with some of HP's low-end business scanners, permits some of the scanning functions to be shared.  Consult the documentation that came with the scanner.  (I know it works, if not very well; I've set up HP ScanJet 6300C and 7490C devices to be shared, using the supplied software.)

Name and model of printer?

I would suggest you to uninstall and reinstall the latest drivers compatible for Windows 7.

You can also run Printer  troubleshooter.

Open the Printer troubleshooter

Open the Printer troubleshooter by clicking the Start button, and then clicking Control Panel. In the search box, type troubleshooter, and then click Troubleshooting. Under Hardware and Sound, click Use a printer.

For further information, visit the below mentioned link:

http://windows.microsoft.com/en-US/windows7/Open-the-Printer-troubleshooter

Printer Issues: http://blogs.technet.com/b/markrussinovich/archive/2010/04/12/3324570.aspx

Run the Printer Fix it from: http://support.microsoft.com/gp/printing\_problems?entrypoint=WHHT

You may refer the below mentioned links.

http://windows.microsoft.com/en-us/windows7/Install-a-printer

http://windows.microsoft.com/en-US/windows7/Find-and-install-printer-drivers

http://windows.microsoft.com/en-US/windows7/Change-your-default-printer

http://windows.microsoft.com/en-US/windows7/Printing-to-the-correct-printer