coordinates - Why does QGIS 1.8.0 crash when I try to set up CRS on Win XP?

I have a problem with my qgis 1.8.0. When I click on any button that set CRS or try to set the coordinates on the fly, qgis crash. I try to uninstall the program and re-install it again using standalone.exe and the osgeo4w-setup installer but the problem persist. My OS is windows XP ice.

Thank you, I hope to not have to format PC!