Dinamic urls doesnt work

I think its the hosting or some file that i failed to upload right, but it doesnt seems to work (The Dinamic urls, like post or pages)
I have php5 if is needed more info tell me.

Pease, i need help!!! My site has been down for 3 days, problems with databeses, and everything else, i just change of hosting (By the way, how good is HostWebSitesFree.com? i know, i have to move to a pay one…) i move the database and all the files; what could be the problem????