Problem with wireless keyboard?

I just bought myself a new computer .. But I didnt get a keyboard and mouse because I already have some left over from when my laptops keyboard broke down ..

As far as mouse, everything works perfectly .. (it`s with wire)

But when I start to use keyboard, somethings not working properly .. It connects to computer, works for a bit and then stops working.. after several seconds it works again .. maybe for a socend and it can stop working again .. But it doesnt disconnect from the computer ..

It`s like the keyboard connection to the adapter is laggy .. But it works fine on my laptop .. it works all the time without lags . As my mouse is working properly all the time, I assume usb ports are working .. But who knows ..

Anyone has any idea ? Maybe some drivers are missing (Driver Checker at least tells me I have all of the drivers).. And it`s not the keyboards fault also I assume, because it works on my laptop well ..

I connected another keyboard through ps2 port .. but I cant keep this keyboard .. So I`d like to get this keyboard working ..

The model is somekind of RAPOO .. It shows "2.4G wireless" something, something .. dont know the exact model ..