so my girlfriends mac laptop bounces in and out of connection with our router. It finds the router but a lot of time it gets really slow or doesn't connect at all. I'm wondering what the issue is here?
It's a Mac....jk.
Depending on what kind of router you have you would have to go to the product website and find the factory defaults to login. Each router has its own interface so it's hard to walk people through changing settings.
The thing is that network can interfere with other networks which are on the same channel. Look for wireless setting and under you SSID you should see channel usually 6 if you use linksys router. If it doesn't work try to use usb wireless adapter and see if there is better connection.