First you need to get into your Display properties. You can get there by going to the control panel and then display properties, or you can just right click anywhere on your desktop there isn't an icon and click on properties. Once you have the Display Properties open you then click on the advanced button at the bottom. Once you click the advanced button you will see a few tabs, click on the one that says monitor. In right about the middle of this box you will see monitor settings/ screen refresh rate. When you select a new rate, such as 72 Hertz, or 75 Hertz then click apply, it will "test" the new settings. If it looks better then you can choose to save the settings or cancel them. Try all of them if you wish, but it is possible that they were somehow changed and make the monitor appear to not be working properly. If you still need any help with this please let me know.
As far as a free LCD, I never said you can get one for free, I said since they are getting cheaper you can get a CRT for cheap or free, if you look for them. Places such as craigslist.org are filled with free items.