A computer system is a combination of software, hardware and the related controls. If you want to validate a computer system, you qualify the hardwarem, asoftware is running on, the software itsself and the related controls systems.
You can validate a software regardless the controls and the hardware. Then you have got the documentetd evidence, that the software does what it is supposed to do. If you want to use the software in your gxp environment, you have to do at least the IQ and some functional tests as well as partially risk based jiustified a pq.
network qualification sounds like infrastructure qualification. The requirements for IS qualification are a little bit different to software validation.
Nevertheless, starting point is always the usr, thats right.