Win 2000 pro / Office XP Errors Help

I am running win 2000 pro / and Office 2000 on system and resentily installed Office XP. Oh god what a mess. Now I keep getting an Error Message that the “refferanced Memory cannot be written” and I also get “Refferanced Memory cannot be read”. At boot up it tells me that I am missing “PSTPRX.DLL” “PNCRT.DLL” “MSWINSCK.OCX” Never had this problem befor it wont let me uninstall some applications. I am at the point of totaly F-Disking my system? Can anyone help