Sounds like you have a bad monitor profile.
Monitor profiles are associated with the monitor by the operating system, e.g., through the Color Management function in Windows. To return to the Windows default, add the sRGB IEC61966-2.1 profile and make it the default.
Then, if you're looking for accuracy, get a calibration and profiling device and generate a custom profile that properly describes your monitor as it operates connected to your system.
-Noel