ticktock 0 Junior Poster

Hey all, I recently received christmas money and have just gathered enough cash to buy a laptop. I managed to find a 2nd hand Asus x5se laptop, it has very good specs and has had its memory upgraded from the standard 2 gb to 4gb and includes a brand new battery that the previous owner bought.

Anyways, I am kinda skeptic on how to check up on how good the laptop is, I mean I can easily check the specs by running cpuz or gpuz or speccy but how can I check some of the other issues on the laptop I don't know about? Maybe the seller is selling the laptop as it having no hidden defects, wherein fact there maybe, and I just don't know of it yet since I don't know how to check up on it.

So I ask what do I check upon seeing the laptop, any programs I should run, algorithms? any nook and crannies I should look upon the exterior and interior of the laptop to make sure I'm getting my money's worth? I would also like to know how can I detect how old the OS has been installed on the machine or maybe how old the machine is overall, irregardless of the number of times it was formatted.

Please help.

Thank you :)