You can use TightVNC, it's client can run from floppy/thumb drive (No install) or it has a HTTP java client and works with non MS OS's

Bob
>I need to be able to view a PC remotely. From any location and from various PCs running various operating systems. The box I need access to is running XP Pro. I'm unable to always load software on the other PCs/Laptops that would need access to this box. What is the simplest solution?