Return open computer to Amazon?

I bought my girlfriend a computer from amazon recently and wanted to set it up for her (charge the battery, etc) before giving it to her. Problem is, I'm going to give her the option to get something else if she wants it, in which case the computer would be returned.

If I keep all of the packaging, and repackage the computer in the box (as new), will Amazon accept it? Their return policy is a bit unclear...

Any ideas?