please help! not a valid win32 app error

[disarray3]

my guitarist purchased an eleven rack and we are trying to install the pro tools 8 software to a previously used pc for recording only that i had SE on. i ran both uninstallers from windows and the SE disk. on my winxp pro service pack 3 machine it says not valid win32 app when i click install. only one user set up and its labeled admin. the box i have with dicks has decal with what i thought was id and serial numbers, but no card inside like the site says. how and what do i do now to get this installed? sorry if this isnt in the correct place. it is my first post and trying hard to stay with pro tools here....