I currently use a wireless keyboard and mouse but on a fresh install of an OS have to revert to PS/2 because the drivers do not install rendering the keyboard useless . I have just a cheap PS/2 that I use specifically for installs . I was fixing a friends pc the other week and the keyboard seemed faulty , no boot light on start up and no response on input . When I swapped to her keyboard everything was ok . I removed my wireless keyboard from my personal pc and tried using the PS/2 keyboard and it wouldn't work . I have the yellow exclamation mark on the driver but updating the driver from the task manager doesn't work . Obviously this isn't a huge issue as I don't use the PS/2 keyboard . On a fresh reinstall of an OS would the PS/2 driver reinstall ?

Is this an OS fault or machine fault ?