You should not try to open the .part files, this will not work.
You need to download all the five parts you see on the download page, plus the reassembler.
Put them all in the same dir and run the run_me_first.bat. This will create the executable which you can run to install PlaneShift.
erm see i have a windows xp with a pentium 4 processor and im not sure how much MB or RAM it has so u know i wanna play but not screw my comp up...so can yall tell me how to check?
1. right click on the My Computer icon on the desktop
2. select properties.
Your RAM should be at the bottom of the screen that appears.