serato can be on 2 computers at the same time

I had a similar problem recently. If it is a Windows laptop try this:

When you connect your Serato DJ hardware to your Windows computer, your operating system may secure your hardware as the default soundcard for playback and recording in Windows. If this happens, Serato software will not be able to access your hardware's soundcard and therefore will not connect.

If you are still having issues, please try the following:

Close all applications
Navigate to Control Panel > Sound
Select your computer's internal soundcard or speakers as the default Playback device
Select your computer's internal soundcard or microphone as the default Recording device
Check the Communications tab to see if you need to set the internal soundcard as the default device. (this is not always necessary, as with some Windows versions there is no option to set a device in this tab)
Open your Serato software and try to connect your hardware

Yes I have don this. But my hardware still wont connect. I got it to connect one time but it went out again. Once in a while it will say error cant connect audio

use another usb cable or try using another Usb port