bad news its not being detected by bios, so i assume its either totally dependent on drivers to function or the extra socket not for power cables is some sort of data cable socket. either way this is pretty annoying >.<

So, no drivers necessary for Linux, but it needs power, a 4 pin connector, is it powered up(?), do other usb accessories work using the card(?).

well we attached the cable that came with it up to the other molex cables. when i booted up my windows drive it didn't say any new hardware was detected.

You wouldn't expect Windows to say anything - it's only USB stuff.
Try Windows to see if it recognizes a USB stick in one of the new ports.

I would say that it seems you can't boot from a USB drive.
I'd suggest that this is is because USB is a very simple interface and doesn't reveal details of the disk behind it.

However, all may not necessarily lost!!!
I think that it might be possible to create a 1GB (or even 500MB) partition on that 80GB disk to hold a /boot partition - noting that the MBR would get over-written.

This would put GRUB and the kernel in a good place.
The boot definitely ought to work BUT at what point would the root directory, / on the USB drive be needed?
Too early and it would be a waste of time.

I really think you need assistance from someone with a more detailed knowledge of things here.

There is another way that would definitely work - but I don't think you want to go there as the Mint install doesn't support it very well.
I'll just mention LVM - but don't go there.

I would say if it's a pci card you have to enable in bios. Also enable boot diagnostics to see if it's picked up by bios. Hopefully the bios will allow the pci with onboard graphicsat same time.

i tried installing the driver onto windows, it appears to be bugged due to it not recognizing when i plug stuff in. i suppose its time i asked about this: the purpose i have for putting linux onto the external drive is so i can carry it around with me so i can boot into linux when i'm on another computer (university, family's house etc) and have all my files and software, but considering all the trouble i've been having simply trying to get it to boot from my main pc it would probobly meen it would be impossible to sucsessfully boot into computers this way due to difforent hardware configurations and such. would it be a better idea to simply get another internal hard drive and use that?

I think that it's the software that is on the usb-drive that's causing the problem. Like I said my external drive used to be an internal drive that I put in an enclosure. The ecosure cost me about $15 us. It boots everything except a mac or any UEFI machines.

oh wow i didn't know you could do that :O

You could save yourself a lot of trouble by just plugging your 500gb drive into the system in place of one of the drives that you had unplugged because they are full. (Skip the USB plug in). Install your system from the DVD on that drive. When you get to the install screen that shows the various drives that are plugged in, it will show your windows drive as "fat32" or "ntfs". If you want to preserve it just as it is, just mark that you want to use it as whichever type it is, call it "
"/windows", do not mark it to be formatted. Install your linux OS on the drive you want it to be on. (If there are only two drives, one will probably be called sda, and the other sdb.) Normally it will write the boot information to sda.

Reboot and you should be given the option (on the "grub menu") to reboot into windows or into your new installation. The normal default will be your newest installation.

Have you thought about Cloud storage for the files you need when travelling around?

(Your external drive can be taken out of its enclosure & put into your computer if they are compatible.)

As a fallback - a slow one - you could boot a live USB stick.
Then plug the external drive into a USB3 port, mount it and use it to hold all your data.

I do this for taking backups as I totally failed to make my USB2 external disk bootable.
( However, it's an old machine & I can't even get it to boot from a USB2 stick - I'm forced to use a live DVD! ).

well I've got my eye on an ssd hybrid drive that should be perfect for Linux and windows to stay on

I have been looking for a solution to your problem.
Maybe thus might shed some light
http://forums.macrumors.com/showthread.php?t=1709803
After viewing that thread I searched to see if your drive supported UASP & couldn't find anything that says it does.

ok, i've ordered the new drive so when it arrives i'll have a completely average SATA drive, hopefully that should solve both the problem with power and resolve the potential speed problem

so I have windows 8.1 on my new drive, so my 80gb windows 7 drive is ok to be overritten