SOLVED* No signal to monitor HELP

Levitation

Prominent
Mar 3, 2017
2
0
520
SOLVED: previous owner wiped the harddrive and left me with no OS.

I admit I'm very much a noob when It comes to PCs but I'm not a moron and I've done about 5 hours of troubleshooting and research.

I bought a built PC yesterday from a friend and the first thing I did when I got home was clean out the entire case of dust. (there was a lot) while sliding back in the tray holding the HDD I accidentally damaged the SATA cable connecting to the back of it. Went to local computer shop, got a new one, hooked it up. Fired up the PC and now I don't have any signal to monitor. I know it worked because he was showing me it working and playing games before I handed him the cash.

EDIT: got it to give me a signal to my monitor, showed a few screens for a couple seconds, then scan device... no device! Then stops at a black screen that says: Reboot and Select proper Boot device or insert boot media in selected boot device and press a key.

Could the sata cable I bought today be no good? Or do I need a disc with windows on it to boot it?