Technically: Yes, ofcourse you can put the SSD int he new system.
There are two problems though:
- Will it boot the OS?
- Are you allowed to?
Will it boot the OS?
It might, it might not. Windows does not like to be moved to different hardware. If you have a very similar system it might work. In some cases uninstalling all drivers helps before moving to a new similar system (and then installing the drivers for that new system). Coorporate environments do this all the time, but usually with a relative clean windows installation and they use something called sysprep. This basically cleans several windows settings to a similar state as 'windows is booting for the first time`.
Are you allowed to?
if you bought a regular windows licence (probably for somewhere between 100 and 200 Euro) then yes. You are allowed to. If the old system came with a limited licence for that specific laptop only then no.
I am not up to date enough with windows 8 licences. YOu will have to look up how windows got into the SSD in the first place and with which licence.
Lastly: There is nothing stopping you from moving the SSD and simply reinstalling (a legal) windows. Just make sure you leave the partition with all your data alone and that you only do a clean reformat and reinstall on the C:\ volume.