YW.
The thing with GIMP isn't that it is all that more advanced than PhotoShop or PaintShop Pro. The thing is the learning curve as to how functions are named. For instance, in Paint Shop Pro, to resize an image you go to the image tab and select 'resize'. In GIMP it is in the same place but called 'scale' instead of 'resize'. The biggest hassle with GIMP isn't that it is an 'expert' level app. The learning is in that it names functions differently which can make them difficult to find.
As to your friend having an old XP system; PhotoShop 2.0 would still not have run as 2.0 was a DOS app that would not run under Windows. Version 2.5 was the first to run under Windows, probably Windows 3.1 as it was released in 1992. It is extremely doubtful that version 2.0 would run under Windows XP which was released in 2001. This is why I question if it may be possible that the PhotoShop version is actually CS2, not version 2.0. Unless your friend had an OLD DOS based system I just don't see how version 2.0 could ever have been used.
CS2 was released in 2007 which makes it seem much more likely if it was used on an XP system with XP being released in 2001.