BOOT failure because i made mistake

[adhd2001]

So yesterday i partitioned my c drive so i could install linux as a second os but when i did that i also accidently made that disk my active disk so now when i try to start it it has no os and i cant seem to boot via usb so anybody have any solutions

 

[superninja12]

get into the bios and select the partition you wish to boot from

 

[adhd2001]

I cant select it in the bios the pc is to old for that it is an hp compac dc5800 tower