Are you using version 1.2.3 of ESF?
Are you using Steam?
Are you trying to run any ESF add-ons?
What game are you trying to install ESF into?
Are you behind a router or firewall?
Are all your drivers updated?
What in-game video mode are you using?
If you have an error message, what is the exact error message?
By including this information in your post we are better able to serve your needs.