As far as can read, the sentence "We fix computers for..." could be understood as they work for a company. Thus, a suitable translation into Spanish would be:
Nos dedicamos a la reparación de computadoras / ordenadores para (X compañía)
You could say, more literally: " arreglamos computadoras para (X compañía)" or "reparamos computadoras para (X compañía)".
That would be "Lo siento, mi computadora no está funcionando bien".
Mi ordenador es lento
computer in Spanish is ordenador -- la computadora
tu arreglaste mi vida
informática
computadora
ratón...
To say 'I want a computer' in Spanish, you would say 'Yo quiero una computadora.'
"Log off the computer" in Spanish is "Salir de la sesion de computadora"
You can say: "Manuel està usando la computadora." which translates to "Manuel is using the computer."
Usar la computadora
Reparacion de computadoras
It can be "programador" or "programadora" for a female.
You could say "¿puedo usar tu computadora?"