It seems that the Fedora installation managed to modify the Master Boot Record (MBR) or installation didn't finish properly or was aborted. You need to restore the MBR by using a Live CD for booting, I guess. Your case can be become extremely complicated, because you have two Linuxes and Windows next to each other. Maybe start out by restoring the MBR for Windows, and then proceed to update it to work with the two Linux installations.
In general: if you just want to test another Linux distro, rather have a first run within a virtual system like VMware.