Solved! Acer Aspire TC 391 ,

[Orlo1984]

I was wondering if I could upgrade the PSU so I could put a gpu into the system

 

[hang-the-9]

Looks like it has a standard power supply in it, and the motherboard has a standard ATX format power connector, so yes you can upgrade it.

I would make sure there are no odd size or cutouts in the power supply, open the case, look over the power supply make sure it looks like the standard ATX ones. Maybe measure the sides to compare.