Nothing shows on screen

Okay I have no idea where to post this so I put it there.
I just built a pc and when it booted up it used my old hard drive, and apparently windows xp was on that. I didn't want it so I shut my pc before it started installing(it was asking me if I heard noises, to check if the speakers were working when i shut it. Now when I try to boot it it starts but nothing appears on screen, I tried removing the battery to reset the bios, unplugging my hdd and it didn't work. Also the speaker does a beep but it always did it when trying to start up, so I don't know why that would be a problem now. What can I do?