explorer 7 wont work on xp

Question

i downloaded explorer 8 and it wouldnt load so i uninstalled it and got explorer 8 of a cd but that didnt work so i uninstalled that and got explorer 7 and it still dosent work

ive tried restarting it

reinstalling it

tried loading it loads of times

but it still wont work.i need to go on it at home (i used public computer) .if anyone has any suggestions pleez tell me

reply asap if u no what to do