Help my computer is acting strange

Arcanine300

Honorable
Oct 30, 2013
164
0
10,760
So i opened up my computer to see how much dust was in it and i unplugged the sata cables to see if there was any dust in the ports (i was just making sure). I then put the side pannel back on and booted my computer and it said "No operating system detected press any key to restart" and when i press any key it boots but very slowly and my icons are blank for awhile text doesn't load quickly etc. It also displays that message every time i boot now. I don't know what happened i was very careful removing the cables and i can't fix the problem so i need help.

My hard drive also runs at 100% most of the time aswell.

I am on windows 8.1

Here are my specs:
amd fx-4100
msi 970a-g46
asus gtx 760
western digital caviar black 1tb
corsair hx650w
corasir vengence pro 16gb 1866mhz
 
Solution
WOW i feel like an idiot now XD i found the problem i had a flash drive in my computer so my bios changed the boot order to usb then hard disk *face desk* all i had to do was change it

Arcanine300

Honorable
Oct 30, 2013
164
0
10,760
WOW i feel like an idiot now XD i found the problem i had a flash drive in my computer so my bios changed the boot order to usb then hard disk *face desk* all i had to do was change it
 
Solution