computer can't find hard drive after clearing cmos

[7Hd]

hi everyone...I am fairly new to the site and thanks for the welcome.  but i do have a major problem.  ok...I was messing around with the cpu clock and voltage (when my computer was still doing ok)...but then something happened.  It won't boot anymore so i cleared CMOS.  and here is where the problem arised.  after entering in all the values into bios and such...(this time, i did not mess with the cpu..haha)...for some reason...my computer won't detect my hard drive nor any of my drives.....i was so fraustrated because i have a lot of stuff in it.    

During boot up...it did ask for a system disk..which i put in...and somehow...it did manage to detect my hard drive...but....i don't want to reformat my drive either.  
so any help would be greatly appreciated.  
Thanks,
7Hd

....I NEED HELP!!!!!  haha.....

[Peccavi]

Plug the cables FIRMLY!  Going to the drives.
You have played around and may be touched them. This may be the main reason. OK, at least with me it always happens so...

[Backdated]

Is this system IDE, RAID or SATA based?

[7Hd]

I'm pretty sure i have checked all the chords and cables.  they were all secure.  it wasn't just my hard drive that the cmos wouldn't detect...but all the drives.  my hard drive is a IDE.  should it matter?  
thanks.

[Backdated]

Go back into the BIOS and ensure that both IDE controllers are enabled and that all IDE devices are set to auto discovery.