MacBook Air-- help?

[miss.aftermath]

So, hello all. First off, i'm new to the whole world of Mac, as you can probably tell.
I got my Macbook air just the other day, and i bought microsoft office for it, the lady checking me out was supposed to tell me how to install it but never did and I ended up leaving the store and forgot to ask as well.
Later on, I got home, did my homework, and researched how to load it. i've gotten as far as needing dvd or cd sharing. I downloaded that and then I went to the installer, began to install, and when it comes to destination select on the installer, there is only one option Macintosh HD. When that is selected, at the bottom of the screen there is a note that says it cannot be installed on this disk. A newer version of this software already exists on this disk.
I've had the same problem when I try to install Adobe flash player as well, and the same note comes up.
Maybe there is something i'm just not getting?

[cwa107]

I'd be willing to bet that Office is already installed as a trial - check the Applications folder. If it is, go into Microsoft Office 2008 => Additional Tools => Remove Office. Once it's gone, then try reinstalling.

[miss.aftermath]

Unfortunately, it's not there. :/
I looked there and searched on the Macintosh hard drive itself, and found nothing. I'm stuck.

[cwa107]

Unfortunately, it's not there. :/
I looked there and searched on the Macintosh hard drive itself, and found nothing. I'm stuck.

That's interesting because Microsoft Office trial has been preloaded on both of the Macs I've purchased. Are you saying the removal tool isn't there or that the folder is missing?

[6string]

So typing microsoft office in the finder search field brings up nothing?