Our old 20 gig hard drive isn't cutting it for us anymore. I got onto newegg and found this

Now, my question is this: How do I find out if it is capable with my computer. I have a Dell Dimension 4400 so it's new so I think i'll be okay. Just don't want to buy it and open it to only find out it won't work. I looked in the manual for my computer and it has an extra hdd bay so I can have a total 100 gigs (I think that's how it works) but it doesn't specify which type it has to be (if it has to be a specific one at all).

Thanks

It will work. Yes, you'll have 100 gigs.

Note that the link you posted shows that the drive is OEM, meaning that it doesn't come with any cables/screws/documentation. You probably won't need a cable, since the one in your computer will probably support a second drive. You will most likely need screws to mount the drive. You'll also probably have to set the jumpers on the back of the drive to "slave" (or else "cable select"). The jumper is probably on "master" by default - you only use this setting if the harddrive ends up on it's own IDE cable. Finally, the drive may come unformatted, meaning you'll need to format it from WinXP (I can help you with this if needed).

If you go to the manufacturer's website, you can download the documentation for the hard drive. It will explain all of the above in more detail.