I have perfect wifi, and on my old computer my wifi works perfectly. On my brand new gaming pc it is constantly timing me out. I join a server, and after a while everything freezes and I get timed out! HELP!
Wifi's not the problem, something to do with the computer. I've tryed deleting Windows Firewall, anything blocking it or stuff like that but nothing works. Maybe Java is blocking MC, but I don't know how.
Are all of your device drivers, especially the video card, up to date? Have you completed all of the OS updates? Have you updated your java to the most current version? Make sure, if applicable, you get the 64-bit version of java, as the 32-bit version will not work for everything running on a 64-bit OS.
Funny thing, I have a wireless wifi card instead of an Ethernet cable, and I moved the card, instead of in the back of my pc usb slot, to the front. I have n0t gotten timed out since, but I still have occasional ping spikes (1000+) and my ping is very volatile. Sometimes it's 120, then it's 300, then it's 450. How in the world did this happen? I'll check for all the things you mentioned in your post now.
Run the following: dxdiag.exe and tell me the output. It'll get the spec for your computer, as well as driver versions.