New computer!!! Yay

[*The.Doctor]

Some Dell's have a little sticker on the back of them thats stuck across the back and the side of the case that opens, so if you open the case it tears the sticker. Other than that sticker, there not going to know if you opened it up or not unless you tell them, or if you break something thats pretty much impossible to break without opening it.

[Mastershroom]

I wouldn't think it's much of a problem. RAM is generally relatively simple to install.