Windows 7 - Disk Boot Failure, Insert System Disk And Press Enter

I pulled the side pannel off my comp last night to clean the dust off side fans. I somehow accidently unplugged the main hard drive SATA cable. Without knowing I tried to start my computer up and of course got an error message. I plugged the HDD back in thinking it should boot up fine this time. Boot up starts up as normal and goes to the ASUS Crosshair screen where you can enter Bios then goes to a black screen that states "Disk Boot Failure, Insert System Disk And Press Enter" My hard drives are all hooked up and I've gone into BIOS to make sure nothing changed. I even set boot priority to CD Rom and put Windows 7 system disk in. Every time computer turns on though I get same Disk Boot Failure message. I even tried using an older Vista CD hoping it might ask me if I want to reformat. Only thing I'm able to do is go into Bios and change things around, but cant figure it out.

Are you sure you put it back as it was before, worth double checking
Check all other sata and power leads to make sure their pushed fully home

In bios can you see all devices HDDs and optical drives

all SATA cables are in the same spot they were before I unplugged main HDD from SATA port 1 and plugged it right back in. All devices show up in BIOS and I can change all their settings as normal. Everything looks jus as it was it just wont boot.

In the mix up of having multiple hardrives I plugged wrong SATA cable into the main so computer couldn't boot up.

And there you have it.... I've been working on computers on for more than 20 years and still do things like that sometimes (probably because I never bothered to get an education on computer repair, I just do it)

Glad to hear you got it sorted