I installed WiFi some time ago, but the Win 7 PC downstairs did not have WiFi capabilities. I bought an adapter
Can you please give the model of "adapter" you bought?
From the rest of your post I assume it's perhaps a Linksys WirelessN USB AE1200 or AE2500. Is that what it was?
and it worked fine for a short time so I bought and installed another adapter. The other night it failed again
What exactly was the symptom of "failure"?
There are several icons in the System Tray (notification area) relating to wireless communication. There's the Network icon, and also the wireless connections icon. What was the visual state of each one when you had "failure"?
In other words, was there a small red X over it, was there a yellow exclamation mark, was there some other small overlay indicating a problem? If you hover the mouse over the wireless connections icon, what is the flyout help that appears? Same with hovering the mouse over the network icon... does it show "no internet access"?
If you hover the mouse over the wireless connections icon (i.e. the one with the five bars), what does the flyout text show? If you left-click on that icon, do you see your router's wireless network as connected, or at least available for connection? If you right-click on that icon and select STATUS, what appears?
so I dragged out my Ethernet cable and hooked it up to the PC. I contacted Linksys and went to Office Depot to make sure that I plugged the other end into either the router or the modem.
Please provide the name/model of your router, as well as the name/model of the modem, as well as your service provider.
If you're using a router, then the router's single WAN (i.e. Internet) port connects to the single ethernet port on the modem with an ethernet cable. And if you're using wired ethernet cable connection from PC to the router, then your PC plugs into one of the 1-4 ethernet (i.e. LAN) ports on the router with an ethernet cable.
My Netbook and laptop still have WiFi as does my phone. But I can NOT get Internet on the PC downstairs with the Ethernet cable. I took the second adapter out before attaching the Ethernet cable.
This is a desktop PC downstairs?
Generally speaking, network connections are not "hot swappable". This means you generally cannot just pull things out and plug them in without first shutting the machine down completely to remove the USB wireless network connect, or to reconnect an ethernet cable to restore wired connectivity to the router where previously you had been wireless.
It is always the right and prudent thing to do to shut your system down first, before changing network connections. Much goes on at Windows startup relating to networking wired vs. wireless, and this is not normally performed at other times. You can easily switch on-the-fly between available wireless networks (i.e. WiFi SSID's from nearby wireless routers or wireless access points), but going between wired and wireless or vice versa is another matter entirely.
So again, did you shutdown your machine first before pulling the Linksys USB wireless adapter and putting back the ethernet cable, and then reboot after the change? Or did you try to do it "hot", i.e. on-the-fly just by doing the changes while Windows was up and operational in one of the two states?
Before installing WiFi, all of my computers used an Ethernet cable, so why not now?
Sometimes Windows wired connections develop an issue, where they just don't start... even though they used to, and even though you can "kick start" them into life and they will then work perfectly, at least until the next re-boot at which time they once again just don't start.
One trick for kick starting them which might work for you is to DISABLE and then ENABLE them:
Start -> enter "network connections" (without quotes) in the "search programs and files" field -> press ENTER
This will produce the Control Panel -> Network and Internet -> Network connections dialog. Your specific wired ethernet network adapter (i.e. the wired NIC in your PC) will show up there (with its hardware name shown typically as the third line of one of the objects shown), and the first line of that object should say something like "Local area connections". It may have a red X on it or not, so which is it? It may say "connected", or "disconnected" or "network cable not plugged in". Anything?
Anyway, if you right-click on that wired connection object, select "DISABLE" from the popup menu, and then wait a bit. You should probably see a little red X now appear over the network icon in the System Tray. The object in the Network Connections dialog should also show DISABLED.
Then, right-click again on the wired connection object and select "ENABLE" from the popup menu, and then wait a bit for things to stabilize. Does the little red X now disappear? Does the Network Connections object now show ENABLED, and perhaps show a "network name" on its second line? If you hover your mouse over the network icon in the System Tray, does it now show "internet access"?
Finally, why do you want to go wireless for your downstairs desktop PC, when previously it always was wired connected to the router? Just to eliminate the ugly cable?
Just curious.
Please provide the answers to my questions above, just so it's a bit clearer exactly what is going on.
