Ahci Driver Windows 7 64 Bit

Hi all - I was wondering if someone could help me with this problem: I have a coolmax external drive enclosure with a Seagate SATA drive that is running on a dell E6400 with windows 7 64 bit. ESATA will not work in AHCI mode and bluescreens the system if i change it in the bios. The system is currently running in IRRT but in that mode the drive will only work in USB which is too slow. (I need to run VM's from the drive) I need to be able to make this work without reinstalling the OS in AHCI mode. Is there any way to do this?
Gateway E-475M Notebook Intel SATA AHCI Driver 7.0.0.1020 for Win XP 32/64-bit It is highly recommended to always use the most recent driver version available. Do not forget to check with our site as often as possible in order to stay updated on the latest drivers, software and games.
I have tried manually loading the drivers but in windows 7 they don't appear to 'stick' when I reboot Windows goes back to the standard intel driver (Non AHCI) and bluescreens if I reboot. Synopsys tcad torrent download. I made sure any registry settings that need to be modified are modified, and I think I have done everything in my limited power to try and get this to work.I did change the driver one time and got it to work but after a couple of times I rebooted it blue screened again.
It seems there is something different maybe in my machine i don't know because I have 5 coworkers who have the exact same system and the exact same drive and enclosure running Windows 7 64 bit and they were able to change from IRRT to AHCI and get theirs to function with very little difficulty. When i tried to follow the same method I found that my OS configuration was different (i.e. Registry settings that needed to be change already were changed) and I was unable to get it to work properly. So i KNOW it CAN work I just need to know how to get it to work without expending a lot of additional money and time beyond what I have already done. Can anyone please help me?