Having issues with wireless on my iMac

Question

Hello,
I have had my iMac since August of 2011 and sometime last year I decided to upgrade to Lion (like maybe a two three months after I got it). The upgrade was rather smooth, with the big exception that ever since I have updated to Lion I have had annoying issues with my Wireless Internet. I know that this is a known issue, but I am hoping to get some answers/assistance... maybe there is something I can do in my particular case.
Originally the issue was that whenever I turned on the computer from sleep, the Internet was disconnected. Now, I have a been a iMac/Mac Mini user for over 7 years now and I never had such issue, you turn on the computer, the Internet goes on with it too. It would require me to manually connect to the Internet evertime by selecting our Wireless Network from the drop-down menu.
About, I want to say, two months ago? Apple sent out a fix via Software Update that said it would correct issues with the iMac wireless not turning on when returning from sleep, "Finally!" I thought and I enthusiatically waited for the update to come.... and it came and it just made things worse. It doesn't make me manually connect the Network anymore, but it takes it sweet time connecting (like a minute some times) and other times it will connect and disconnect a few times before not giving any more problems. Oh did I mention sometimes it just decides to turn off for no reason at all? Yeah, happens a lot. Especially annoying when I am excersizing my nerd rights and playing an MMO and suddenly get booted from the game because for whatever reason my Internet decides to log me off.
This morning, it was connected to the Internet but websites were taking forever to download, eventually Chrome was just giving up and saying it couldn't connect... but the Internet was connected (full bars if it makes any difference). I tried turning Airpor on and off but no dice. Now, this totally sounds like a router issue, except my boyfriend was sitting behind me on his brand-spanking-new HP and he was happily surfing Reddit or whatever he does whilst online, no issues there.
So the question is: Is it possible to "revert" back to the time before the update? I guess I could use Time Machine, but uhh, I dont want to revert the whole computer. So how exactly would that work (Time Machine noob here)? Is it possible to look at updates done and simply remove? Also, is there a more amicable fix that packing the whole thing up and taking it to the Genius bar? I'm willing to try some DIY fixes as long as they dont involve messing up with the whole network, especially since no other device is having issues, just this one and we have a lot devices.

Answer 1

If you have a router that can do a 5GHZ network try it. There seems to be less interference in that part of the spectrum.
Apple DNS Servers:
208.67.222.222
208.67.220.220
Wireless Improvements
Move the Base Station If interference is particularly bad in one part of your house or office, move the base station to another location. But this can be tricky if your AirPort base station has to connect to the broadband feed coming into the house and that feed happens to enter at a particularly interference-prone spot.
Use the 5GHz Band Compared with the 2.4GHz band, the 5GHz band is practically empty. The newest AirPort Extreme Base Station is one of the few Wi-Fi base stations designed for home use that work in that 5GHz band. All of Apple’s Core 2 Duo laptops and iMacs (except the discontinued 17-inch 1.87GHz model) can also use the 5GHz band; with the build-to-order wireless option, so can the Mac Pro.
To switch to the 5GHz band, launch AirPort Utility, select your base station, and switch to Manual Setup. Click on the AirPort button and select the Wireless tab. Select 802.11n Only (5 GHz) from the Radio Mode pop-up menu. Click on the Wireless Options button and select Use Wide Channels. Click on Update to restart the base station.
Currently, no Mac-compatible adapters enable you to use the 5GHz band in older Macs or with older versions of OS X.