Digital BW, The Print

I just installed an upgrade to Photoshop CS and am wondering if I can get some help 
with this OT question.  I now seem to have 3 copies of PS installed on my Mac G4 
Powerbook - PS 7 in OS-X, PS 7 in OS-9, and now PS 8 in OS-X.  Given that they take 
roughly 250mb each and I am running out of disk space, can anyone think of a 
reason why I wouldn't dump, say, PS 7 in OS-X? 

(I haven't checked but presumably there is an uninstall function in the original PS-7 
cd....?)

BTW, as I think back to earlier discussions on this forum, it is interesting that product 
activation is only required for Windows users...

Thanks in advance

Steve