If you are using Zone Alarm, right click on the ZA icon in the system tray (lower right corner of screen) and then click "Shutdown ZoneAlarm", and see if this fixes your problem. If this does not work, try the following with Zone Alarm: Open the ZAISS control center, go to Privacy, then temporarily turn off Ad Blocking and Cookie Control, and see if that fixes your problem.
If you are using Noton Internet Security with the Add-on Pack, be sure to turn off the Pop-up Blocker. Some users have reported that they needed to uninstall the entire Norton Add-on Pack.
If you cannot get anything at 192.168.1.1 then perhaps this is not your router's address. Go to "Start" > All Programs > Accessories > Command Prompt. A black DOS box will appear. Type in "ipconfig" (with no quotes), then hit the Enter key. Look at the "Default Gateway". Is it 192.168.1.1 ? Point your browser to the "Default Gateway", then login to your router.
If the above fails, disconnect your modem from the router, and try again. If this corrects your problem, then most likely you have a "modem-router" rather than an ordinary modem. Check to see if your "modem-router" is using the same 192.168.1.x address space as your Linksys router. If it is, then report back with this problem, and also state the make and model of your modem-router.
If all of the above fails, power down your entire system, unplug it from the wall, wait one minute, then power up and try again.
If all of the above tips fail, you need to reset the router to factory defaults. Power down the router and disconnect all wires from it. Wait one minute. Power up the router, allow it to fully boot (1-2 minutes), then press and hold the reset button for 30 seconds, then release the button and allow the router to reset and reboot ( 2-3 minutes). Power down router. Wait one minute. Connect one computer, by wire, to a LAN port on the router. Boot up system. You should now be able to view the router's setup pages.