Wifi Network Adapter drops out at random times (Windows 7)

OS: Windows 7
Hardware: Sony VAIO
Powered by: AC
History: The computer is about 2 years old and the symptoms described below started either abruptly or gradually some 2-3 months ago.

Symptoms: The network access icon in the right of my task bar will show 4-5 bars of signal strength. I'll leave the computer for several hours and when I come back, it shows 0 bars with a red x over it. I click it, select troubleshoot and the Windows Network Diagnostics window pops up and says "Problems found"; A network cable is not properly plugged in or may be broken" - Detected; "Problem with wireless adapter or access point" - Fixed, upon which the icon goes back to 4 or 5 bars and I resume my network connectivity. This takes all of one minute or less.

However, if I need to do a lengthy download, this unexpected action will stop the download in the middle of the night.

TROUBLESHOOTING STEPS:
1) I tried a side-by-side comparison with another laptop and the Sony VAIO lost the network connection in the manner described above while the other computer didn't.
2) I went to Manage Wireless Networks, removed all networks (including my home network) and then rebuilt the wireless networks by re-entering my home network. I was then able to access my network. However, the wireless network adapter still shut off in the middle of the night.
3) I went to Power Settings/Change advanced power settings/Advanced settings/Wireless Adapter Settings/Power Saving Mode and observed that "Plugged in" states "Maximum Performance"

Thanks for your help.

Aside from Slartybart's fix, it can also be that there are now more access points in your location than before previously. Try optimizing your WLAN channel by selecting the best channel using inssider. This should lessen the drops out or even eliminate it. If possible, also update or WLAN drivers to ensure best performance.

Thanks for everyone's help.

I went ahead and performed the tasks described by SlartyBart and DMHolt57. If I still see the problem I'll try the optimization using inssider.

An IT friend of mine suggested I could use a wireless N USB adapter. Anyone have any thoughts about that? Or would that be a last resort if none of the suggestions in here work?

As you described above the problem started quite a while ago. Did you ever try a system restore?

The wifi dropped out again. So that rules out the suggested fixes of Slartybart and DMHolt57. So I'll try the suggestions of theveterans and run inssider. I just updated the drivers at Device Manager/Network Adapters. There were three: Realtek, Microsoft and Atheros. Windows was able to find the current drivers for Realtek and Microsoft and updated those. But Atheros. What's that?

Could this potentially be a registry issue?

Someone else here suggested doing a system restore. If I recall, a system restore will only restore to specific dates. Doesn't it also wipe out any new applications installed between then and now? If what Slartybart and DMHolt57 suggested doesn't fix the problem, then why would a system restore likely fix the problem? Could it possibly be a registry issue?

theveterans said:

Aside from Slartybart's fix, it can also be that there are now more access points in your location than before previously. Try optimizing your WLAN channel by selecting the best channel using inssider. This should lessen the drops out or even eliminate it. If possible, also update or WLAN drivers to ensure best performance.

I've installed inssider and am running it. I do see my router on some of the channels. But there doesn't seem to be a way of telling what channel I'm on at the moment.

I'm curious if my router will show up in inssider when I experience the dropout. When it drops out, my router doesn't show up in the list if I click on the status bar at the right side of my task bar. But it does show up in Manage Wireless Networks.

Are you suggesting that my router is available on a number of channels, and it doesn't auto shift to another channel when there becomes a problem with one channel? (e.g. it's running on channel 1, and when channel 1 has a problem, it doesn't auto shift to channel 3). Even if this is what it's doing, how could I do a workaround?

Slartybart said:

InSSIDer is a good tool to tell you about channel traffic. I don't know about optimizing with it - but you can decided if channel 1 is overcrowded and make a change to a less crowded channel. Be careful though - channel 3 might look less crowded, but you'll actually overlap more channels - thus more traffic.

I've often thought about getting an N USB adapter mainly becasue my builtin adapater is single band and my router is dual band. I could be getting mush better connection if I found an affordable dual band (2.4 +, 5Ghz) plugin. Of course the latest generation after N is AC, so again price would be a decision factor to move up.

But sure, it might be worth investing in the USB adapter. It's been said that matching the adapter card and router card (both broadcom for example) also improves connectivity. Mine match by chance - can't say that it is true though - I had GREAT connectivity to a Belkin router.
Anyway...

I also thought about your move. On an oft chance, dbl check that the location (Control panel->Region...)of your machine is UK. This shouldn't present any problem machine to router, but further downstream - who knows?

Questions about inssider:
1) How can I tell which channel my network is on? (I see it on multiple channels)
2) How can I change from one channel to another?
3) Does the network automatically change from one channel to another when necessary?
4) When I experience a dropout (as described above), will I even see my router on inssider?

So let's say after the dropout, my router still shows up on inssider. I still have to go through the troubleshooting steps and wait about a minute before I can connect to my router.

Now let's say after the dropout, my router does not show up on inssider. I still have to go through the troubleshooting steps and wait about a minute before I can connect to my router.

That being said, just how can inssider be of help in fixing the problem?