Amd model 4 thunderbird socket A cpu 1400 mhz
Clock multiplyer 10.5
Voltage (Vcore) 1.75
The Abit Kv7 does NOT offically support your model cpu however from what you have described the bios is recognizing it and it seems to be working because the bios sees the drives and other settings but windows don't find the sata drive. I think your problem is you are not loading the sata drivers. I will get back to you on this but for now lets get the bios correct.
In bios soft menu set up
set cpu fsb clock to 133 mhz ( I believe you set this already)
Then under power supply set the cpu core voltage to 1.75
Then under Advanced Chipset Features goto Dram Clock/Drive Controll and press enter now set the dram clock to 133 mhz.
Don't forget to save when you exit.
These are the correct settings for your cpu/mobo.If you are able to set all these just like this then I don't think you will need a new cpu even though the cpu is not offically supported because it will be running at correct speeds. The main thing here is the bios accepts its settings and recognizes it.
I will be back in a bit with more on the sata situation