Gateway Laptop / Popups Started Coming Up, And It Kept Freezing

My grandmother bought a crappy old gateway laptop with XP on it (for 3 times what it was worth) from some guy she met. The whole thing was screwed up and practically unusable when she got it so she asked me to fix it. I already set up a working admin account and made it so it can do basic functions and everything last week. I've spent a lot of time on the microsoft websites help section trying different methods to fix different problem, finally got it to work with internet. But, assuming there are two versions, I think they installed the desktop version of WinXP on it.. It doesn't have any of the normal differences an XP laptop has vs an xp desktop, like it has no battery reading, and refuses to acknowledge it's a laptop and has a battery thus refuses to charge the battery, so it must be plugged in to work. I don't know the first thing to how to fix that. Also, I'm pretty sure these things come with wifi, it's not that old, it's a M405 like this one. It has no indication of capability to connect to wireless internet, so I have to keep the ethernet cable in at all times too.IE fails and as soon as I got it connected to the net 1000 popups started coming up, and it kept freezing going to websites and I kept having to ctrl+alt+del it, so I got safari and it's working a lot more smoothly.