Windows 7: set correct monitor model?

How do I tell Windows 7 what model each monitor is, if it has it wrong? I recently set up my new PC (Win 7 Home Premium 64bit), with a GeForce GT 520 video card. I started with 1 monitor then added a 2d. The main monitor is Acer S242HL. Second monitor is older Samsung SyncMaster 2253LW. The system showed the main monitor okay but just had "Generic PnP Monitor" for the second monitor. Today I tried to fix this by downloading drivers for the SyncMaster from Samsung website and installing them (don't remember the steps). Result was a surprise: the system still shows Generic for monitor 2, but now it thinks monitor one is a SyncMaster 2253LW. I can't seem to find a window/button anywhere to tell it that it is something different. Thanks for your help Ted

Right click the monitor in "Devices and Printers". Click "Properties", click the "Hardware" tab. Click "Properties", click "Change settings", click the "Driver" tab, click "Update driver". Click "browse my computer".
You can search or "let me pick" as long as you know where you downloaded the driver file to.

That should work. It's what I had to do for my computer.

Thanks, Havoc. This worked fine, restoring my system's info on main monitor to "Acer S242HL" with all its properties.

I wish I could do the same for the Samsung but searching the web it seems to be too old to have a Windows 7-compatible driver available. Oh well, sooner or later have to get a new monitor, that's all.