ArcadeVGA is a video card, that was made specifically for Windows, that allows people to use an old arcade monitor, typically using a 15Khz signal.
Most modern PC video cards output a 31Khz or higher signal, which is incompatible and in some cases harmful to real arcade monitors. As video cards evolved, 15Khz signals were abandoned by card manufacturers as they were no longer used by modern SVGA monitors. This can make it difficult to get standard video cards to display correctly on an arcade monitor.
ArcadeVGA supports many arcade resolutions used by MAMEtm and other emulators, so you don't need any software scaling in most games. This results in games being displayed on your arcade monitor exactly as they were originally intended.
Some resolutions used by certain games may not work on your arcade monitor, so these may need to be disabled with a resolution tool.