When I click on the network icon nothing happens. Please help ASAP.

Hey, So recently my computer wouldn't start up and was saying "BOOTMGR IS MISSING | PRESS CTR+ALT+DEL TO RESTART" and then I just left the computer on for a couple days and forgot about it. And just an hour ago I started it up again just seeing if it would work, and it did. It started up and I was really happy. But I got a D-Link wireless network adapter that I connect to the tower because I can't get an Ethernet cable to reach up stairs, So I have to connect to my wi-fi. BUT when I click on "Connect to a network" nothing happens. I can't Set up a new connection or network, and when I click on the network icon on the bottom bar nothing happens. I do NOT have the Windows 7 Ultimate Repair DVD. So I can't use that. Please help! :)

You can create, and burn a windows 7 ultimate repair dvd from your system, or download and burn a windows 7 ultimate .iso as well, they are legal.

Thanks. I didn't know it was legal, otherwise I would've done it a long time ago! Now is there a difference between burning it on a CD or a DVD?

First type Troubleshoot in Start Search box, then run the troubleshooter for Connect to the Internet, follow its instructions or report back what it says.

Is the driver installed in Device manager and not in error (!)? Driver Install - Device Manager

Reboot and tap the F8 key repeatedly to access System Recovery Options
to run Startup Repair a few times to see if it sorts the problem.

You would have to burn the System Repair Disk CD from within Win7. You can burn the installation DVD for your licensed version to use for repairs or reinstall from Step 5 of Troubleshooting Windows 7 Failure to Start which also provides everything possible for starting unbootable Win7.