I googled it and found others with the same issue. As you didn't reveal that detail I'll stop here.
I have an issue that has baffled me for the last year. I have a Lenovo T420 running Windows XP service pack 3. It is a laptop issued by my employer. Since it has a Windows 7 sticker, I assume it came preloaded when it was purchased and then was reloaded with XP. The wireless adapter is Intel Centrino Advanced-N 6205.
The laptop connects to wireless networks with no issues everywhere I travel...client offices, airports, hotels, restaurants, etc. However connectivity to my home network is another story. I will be connected, and then the connection inexplicably just drops and I get the dreaded "Limited or no connectivity" alert message. A while later, the connection re-establishes itself and then the pattern repeats itself. I can notice no pattern to the issue...the connection can sustain for hours or minutes, the "limited connectivity" alert can last for minutes or hours. Rebooting sometimes helps, sometimes not.
I have many other devices connected on my home network...Windows 8 desktop, laptops with Wiindows 7, Apple macbooks, ipads, android and apple smartphones, home theater AVR, blu-ray DVD Player, network printer, network backup drive, etc. No other device ever has a problem connecting and sustaining a connection to my home network. I never have this problem with the Windows XP laptop anywhere other than on my home network.
What in the world could possibly be the cause of this frustrating mystery?