Don't get panic when you see this thing, and also don't consult customer care or some other repair shop to waste some bucks.

Usually this error will be found when you made a unsuccessful attempt of dual booting your Mac with Windows.

To fix this error, restart your Mac and hold down option key, after hearing chime on booting.

If you don't want to install windows, then select the Mac Recovery partition. Then from the menu on the top, select the boot disk option and select the drive in which Mac is present. Restart and enjoy...

If you wish to install Windows, then insert bootable disk and select the Windows partition that you had created using boot camp, and proceed with installation.

In both cases you will be able to boot normally.

Case 1: If you are on a internet connection that doesn't require any proxy settings, everything works fine.

Case 2: If your internet connection requires some proxy settings(without authentication), then try this method:

Open internet explorer and set the proxy under Internet Options>Connections>Lan Settings.

Now open Command Prompt with Administrative privileges(On start screen type "command prompt", right click on the command prompt app and click on "Run as administrator" which is visible on the bottom of the screen). Now type the following command and press enter.

netsh winhttp import proxy source=ie

Restart the PC and check out.

Case 3: If your internet connection requires some proxy settings with username and password, then try this method:

1. Install fiddler
   
2. Now please install this addon
3. Open fiddler and click on Win8 config, then click "Excempt All"
4. Restart your system
5. Set the proxy details in proxyfier or proxyfire
6. Always open fiddler first and you can use it in tray with CTRL+M, then proxyfier(remove from startup)

Now you are ready to use metro apps with proxy settings.

I tried to activate my Windows 8 Enterprise, and to my surprise I can't find a way to enter the product key. I later found this method to be useful.

First open the command prompt. To do so, press Windows + r key and type cmd and press enter, or just press Windows key and type command prompt and hit it. Now type the following command and press enter:

SLUI.EXE 3

Now you will see a window prompting you to enter the key. Enter the key and press activate. Bingo...

Safe Mode is a great way to get into your system when something won't allow you to start up normally. Troubleshooting becomes a breeze when corrupted drivers and files aren't loaded that prevents a system from functioning. It used to be as easy as pressing F8 when the system starts up, but doing so with Windows 8 will take you to Automatic Repair Mode. The trick to getting back to good old fashioned Safe Mode? Hold down the Shift key and press F8 while booting up.

This takes you to the Recovery mode. Select "advanced options," then "troubleshoot," then the "advanced options" again (there are a lot of advanced options). Select Windows Startup Settings and finally the Restart button. This will reboot the computer and give you the option to boot into Safe Mode.

If you need to get into Safe Mode from within Windows, open the dialog box (the Windows key + R) and type "msconfig" (no quote marks). Select the Boot tab and check the Safe boot box. The system will continually boot into Safe Mode until you go back and uncheck the box.

Create a shortcut on your desktop (right-click, go to New, then Shortcut). Enter "shutdown.exe /s /t 00" as the location of the item, and press Next. Now name the shortcut (prefereably "Shutdown") and press Finish.

Right-click the shortcut, and navigate to Properties. Choose Change Icon in the Shortcut tab, and then OK to leave the warning box. Choose an icon of your choice from the list. In the screenshot above, you'll see we chose a Power button.

Right-click the shortcut again, and select Pin to Start. You can place the icon on your Start screen wherever it's convenient. Clicking it will instantly shut down your computer.

For shutdown : shutdown.exe /s /t 00

For restart : shutdown.exe /r /t 00

For Hibernating: shutdown.exe /h

One of biggest complaints about Windows 8 is that it boots straight to the Start screen—an annoyance for many committed desktop users.

To boot into the Desktop directly, just follow this simple procedure. Go to the start screen and type in schedule to search for Schedule tasks in Settings. Click on Task Scheduler Library to the left, and select Create Task. Name your task something like "Boot to desktop." Now select the Triggers tab, choose New, and use the drop-down box to select starting the task "At log on." Click OK and go to the Actions tab, choose New, and enter "explorer" for the Program/Script value.

Press OK, save the task, and restart to test it out!

The Start Screen is full of nice, big, chunky tiles that represent all your apps. The tiles are easy to see in small groups, but what if you have hundreds of apps installed? Most will be hidden from view, unless you want to do a lot of scrolling. Enter the new semantic zoom feature. If you’re using a touch display, squeeze the Start screen with two fingers to receive a bird’s eye view of your entire screen contents. And the feature is also available to mouse and keyboard users: Simply hold down the Ctrl button, and use your mouse wheel to zoom in and out. Also holding Ctrl button and pressing + or – will work.

Categorize your apps 

Your Start screen can become a cluttered mess if you collect too many apps and other elements that have been pinned to the screen as tiles, so take advantage of built-in organization tools that let you divide everything into labeled groups.

First, drag all the tiles you want to assign to a single group to the far right-hand side of your Start screen in vacant territory; the OS should sequester the tiles together. Once you're satisfied with your assembly, use semantic zoom (described above) to get a bird's eye view of your desktop. Now right-click the group, and select the "Name group" option on the left of the bar that appears below. Type in the name, and enjoy your newly organized Start screen!

Using Windows 8 is painful unless you are on a touch screen device. If you feel Windows 8 is really complicated and it’s hard to find the things on it, then you must try some shortcuts instead of moving your mouse here and there and keeps on clicking to find them. Here is a list of shortcuts you might find useful:

• Press the Windows key to enter the tiled Start screen.


• When on start screen, to search a setting or file or app, just type its name. If you are in Desktop mode, just press Windows Key and start typing.


• Windows Key + C: Displays Charms menu.


• Windows Key + X: Brings up a menu of advanced system options, including Windows Control Panel, Command Prompt, Task Manager and File Explorer.


• Windows Key + I: Displays the Settings menu for the current app. For example, if you’re in Internet Explorer 10, this key shows Internet options. If you’re on the Start menu, it shows general OS settings.


• Windows Key + Q: Brings up the apps search menu that allows you to search your list of installed programs.


• Windows Key + D: Activates desktop mode.


• Windows Key + Tab: Brings up the Task Switcher and toggles between Windows 8-style apps.


• Windows Key + H: Brings up Share menu for the current app. For example, hitting Windows Key + H in Bing Maps, lets you email or share map information on social networks.


• Windows Key + M: Opens desktop mode and minimizes all windows.


• Windows Key + W: Opens universal search menu and sets it to search settings.


• Windows Key + F: Opens universal search menu and sets it to search files.


• Windows Key + R: Opens Run menu where you can launch programs by typing in their executable file names.


• Windows Key + E: Opens File Explorer to the “My Computer” view which shows all your drives.


• Windows Key +Number Key (1-9): Switch to desktop mode and make the Nth application on the task bar active where N is the number key you hit and 1 is the furthest taskbar icon to the left.


• Windows Key + . (period key): Docks the current Windows 8-style application to the right or left, depending on how many times you hit it.


• The Windows key + "," (that's the comma sign!) makes all current windows transparent, giving you a peek at the desktop as long as you hold down the Windows key.


• Windows Key + Z: Brings up app menu, which shows contextual options for the active app.


• Windows Key + L: Locks your computer and shows the lock screen.


• Alt + F4: Close currant app.


• The Windows key + Print Screen takes a screenshot and saves it in a Screenshots folder nested in your Pictures folder.


• To take a screenshot on a Windows 8 tablet, simultaneously press the Windows button and the volume-down button on the tablet chassis.


• The Windows key + Pause opens the system properties page to show you a quick rundown of your specs


• Windows key + K - List available devices, for example a second screen.


• Press Ctrl + Shift + Esc to start exploring the new Task Manager.