When Windows 7 was rolled out by Microsoft three years ago this very day, it was considered a time for celebration. Microsoft was emerging from a very dark time with its troubled Windows Vista operating system, which was long delayed and generally disliked by many users. Windows 7 fixed Vista, and in the process, it also fixed Microsoft.

Microsoft emphasises that Windows 8 is a totally new version of Windows. Besides the traditional desktop, the new OS also includes a new style interface for use with touchscreens - whether its on a touchscreen laptop, all-in-one PC or tablet.

Although not all PCs will be touchscreen when Windows 8 launches of Friday, techies could expect more and more devices to have touchscreens towards 2013, even on traditional laptops.

Here are 8 key differences that the Windows 8 OS will bring to the table.

1. The Windows 8 touch features allow touch support on capable devices on the Desktop with far better response. The start screen is also affected by this feature and included in it is the selection of menu items. For devices without touch capacity, Windows 8 has gestures which allow the touch mice or trackpads to support such commands.

2. Windows 8 Start Screen features the same kind of live tiles and data found in Windows Phone's home screen. The Recycle Bin and Taskbar still appear, while the Start button shows up when the user hovers the mouse pointer in the bottom left corner of the screen. The Start Screen can be used as an application launcher for desktop apps, or Windows 8 Modern UI apps.

3. Better Monitor Support which allows multiple monitor use with different views. That means the user now have the Start Screen on one monitor and the desktop in another or choose to have the Windows 8 Desktop and taskbar on both screens. The user can also put a different background on each screen if he has multiple monitors.

4. Windows 8 Charms is a key arrival in the Microsoft OS. These Charms appear when the user moves the mouse over to the right hand side of the screen or swipe in from the right on a touchscreen. They enable the user to access the Start Screen on a touch device. Other buttons are Search, Share, Devices, and Settings which provide quick access to these functions on touch and pointer-driven displays alike.

5. The Windows 8 Search and Social feature makes the Search function not only available in Search charm but also through the Start Screen. Simply type and the results on screen for programs and files appear. For social networking, Windows 8 supports Facebook, LinkedIn, and Twitter natively, so the user can browse social updates within the People App and elsewhere.

6. The Windows 8 ARM Support feature makes Windows 8 not only limited to x86-based Intel and AMD PCs but will run devices on ARM architecture. ARM chip designs are being used in growing number of devices, and Microsoft is keen to make its Windows widely available, which could also compete with iPad and Android tablets.

7. Windows Store is another key feature of Windows 8. It is offered on both desktop and Modern UI apps, both free and paid. Users can search the Store via the Search Charm, as well as browse through the top free or top paid apps as well as look through apps by category. When apps are updated, the user could download these updates similar to iOS and Android.

8. The Windows 8 has cloud integration which allows access to the new SkyDrive of Microsoft. The app has the ability to save data to and from cloud storage. Office 2013 apps have SkyDrive capabilities included as well. Microsoft also syncs settings of Windows 8 PCs including browsing history in the Internet Explorer and photos can also be shared across multiple PCs.

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