Hi:
Unfortunately, I don't think I will be able to help you with that because W7 should just install on that hardware without the need for sata controller drivers.
However, I could be wrong. You need this driver download for the chipset in your PC, which has the sata raid driver.
http://www.nvidia.com/object/nforce_vista_win7_64bit_15.49.html
Then you would use the free 7-Zip file utility to extract the files from the exe.
http://7-zip.org/download.html
I have downloaded the file and used 7-Zip to break it down.
You will find an IDE folder. Click on that and you will find a Win764 folder.
You will see a sata ide and a sata raid folder.
I guess you can copy and paste the contents of both of those folders to your flash drive and see what happens.
I do not think this is the issue, but I hope I am wrong.
I have never heard of anyone with the nForce 430 chipset not being able to install Vista or W7 for lack of sata drivers.
Good luck.