Wifi issues, multiple reasons why it may not work possibly IP address

so ive been trying to fix this issue for weeks on end. no luck!

first of all, my router is one of the standard comcast xfinity routers. the nicer ones they provide i believe.

ive never had the greatest connection considering i have my rig on the top floor, but it was never horrible till recently. shows full bars yet doesnt connect at all. i tried virus scans, resetting the router, and just yesterday (since i needed a new one anyways) i dropped 60 bucks on a netgear thumbdrive adapter. im picking up some dudes roku a mile away now that things a beast. but no cigar, problems persist.

i brought the rig downstairs and its sitting next to the router now. it works well besides randomly not working for 10 to 20 minutes a handful of times. im on it atm but it aint gonna fly down here, i need it upstairs.

these problems coincided with a new network my wifi picked up. my neighbor mustve upgraded routers or something. i thought it might be interfering with mine considering theres is xfinity as well and is insecure. someone mentioned i should try changing the ip address. knowing little about that i gave it my best shot and i noticed when i enter ipconfig/release there are large amounts of files that say "media state....... media disconnected". and a large amount of tunnel adapters. help pls!

ok i know i messed something up cuz now my ipod doesnt work at all. just saying, it says unable to connect to network. its never said that in all the years ive lived here