The keyboard shortcuts are very useful and once learned, you can't live without them. Most people knows these ones which works with most applications and Windows itself:
Ctrl+C=Copy
Ctrl+X=Cut
Ctrl+V=Paste
...and here's some more of the most frequently used with explanation:
You can switch users without going through the Welcome screen: From Task Manager, go to the Users tab, right-click a user, and select Connect.
Hold down the shift key in the shutdown dialog to change "Stand By" to "Hibernate". Or just press H to hibernate instantly.
You can rename multiple files at once: Select a group of files, right-click the first file, and select "Rename". Type in a name for the first file, and the rest will follow.
Hold down the shift key when switching to thumbnail view to hide the file names. Do it again to bring them back.
When dragging files in explorer: Hold the Control key to force a Copy. Hold the Shift key to force a Move. Hold the Alt key to force a Create Shortcut.
If you create a file called Folder.jpg, that image will be used as a thumbnail for the folder. What's more, that image will also be used as the album art in Windows Media Player for all media files in that folder.
If you hold down the shift key whioe clicking "No" in a Confirm File Operation dialog, the response will be interpreted as "No to All".
To save a document with an extension other than the one a program wants to use, enclose the entire name in quotation marks. For example, if you run Notepad and save a file under the name Your.Name, it will actually be saved under the name "Your.Name.txt" But if you type "Your.Name", then the document will be saved under just that as a name.
Ctrl+Shift+Esc will launch Task Manager.
To close several windows at once, hold down the Control key while clicking on the taskbar buttons of each window. Once you have selected all the windows you want to close, right-click the task buttonyou selected and pick "Close Group".
In the Address Bar, type "microsoft" and hit Ctrl+Enter. Internet Explorer automatically inserts the "http : //www." and ".com" for you.
To organize your Favorites in Explorer instead of using the Organize Favorites dialog, hold down the shift key while selecting "Organize Favorites" from the Favorites menu of an Explorer window.
Press Win+L to switch to the Welcome screen.
Hope some of you will find this useful.