The most common reason for windows 7 printer sharing not working problem is that Windows 7 requires you to enter a username and password to provide access, you can simply bypass this requirement my tweaking settings as described below.
1. Launch Windows 7 Control Panel
2. Navigate to Network and Sharing Center
3. Click Change advanced sharing settings link as shown below.
4. Scroll down and make sure File and Printer sharing option is turned on.
5. Scroll down further below and select Turn off password protection option from Password protected sharing setting.
6. Click Save changes button to save the new configuration and close the page.
Once this is done you can add the Windows 7 printer from any computer running any operating-system (Linux, Mac, Windows XP/Vista etc.) as usual.