I posted about this before, but I've got a bit more information now. I've got a MacBook. I've got internet from the cable company, and a wireless router. These two things seem to disagree with each other, somehow. When I bring home my work computer (also a MacBook) and use it on my home wireless, it works fine, and everything else that I've got connected to my home wireless (Smart TV, Kindle, phone, iPad) also all work fine. When I bring my own laptop to my parents' house and use their wifi, it works fine. However, when I use my laptop on my home network, it gets really slow and keeps disconnecting. If I run Network Diagnostics, that usually fixes the problem for a few minutes (though it doesn't tell me what it did). If I restart my computer, then it's usually OK for a few hours, but then the problem starts again. Restarting the modem/router also sometimes fixes it for a little while, but not for long. Any suggestions?

It almost sounds like it might be something on the network fighting your laptop for mastery of the domain.

Are you using IPv6 and IPv4 in Network connections?

One thing you can try is to turn off ipv6, and in IPv4 set it to DHCP with static IP address, and put in an address out of the normal range your system gives you. (if the router assigns 192.168.2.x, try 192.168.2.100, etc) The highest the last number should be is 254.

At the very least this will let you know if IP address is a factor.

One thing you can try is to turn off ipv6

How do I do that? My options under "configure IPv6" are automatically, manually, and link-local only. It's currently set on automatically.

Hmmm. Try link-local only.

The ipv6 may not be as big of an issue than the possible IP conflict.

OK. I switched the IPv6 to link-local, but haven't changed the IPv4 address yet, and things seem to have improved. But sometimes it's fine for a while, and then starts disconnecting again. What were you trying to test by changing the IP address?

Changing the IP address made it disconnect immediately.

With the IPv6 turned off, it's still disconnecting.

Are you connecting that troublesome computer on a 2.4 Ghz or 5 Ghz network?

Could be that one of the radios is messed up on its wireless adapter and you are able to stay connected at your parent's because it's connecting on the other radio. If you don't know for sure, try disabling one of the frequencies on your router and see if it makes a difference. Course if your router isn't dual band, then that wouldn't be helpful.

What Gud said. Also, many routers let you check for conflicting traffic channels. It could be nearby routers in your neighborhood are using the same channel, causing interference. What model is your wifi modem/router?

The network stack in Mac OS is also notorious for grabbing what is top of the list not what is strongest or fastest. So if you have a dual band network where both of them share an SSID depending upon whether the 2.4GHz or 5GHz is on the top of the list can toss a spanner in the works.