Thats surprising. Try the following:
1) If the older
driver is an .exe file, just double click on it and it should install. You can then check the
driver version in Device manager.
2) You can rollback to the previous
driver.
In Device Manager, locate the device that you want to roll back the driver for.
Right click on the device's name or icon and click on Properties.
In the Properties window for the device, click the Driver tab.
Click the Roll Back Driver button (If it is disabled, Windows 7 does not have a previous driver to roll back to)
Click the Yes button
The previously installed driver will now be restored.