When you browse the Web with Microsoft Internet Explorer, links open with a single click. Yet, when you browse My Computer or My Documents, a single click lets you select a file or folder, but you have to double-click to open it.
If you'd rather single-click to open files and folders, you can change the setting on your mouse (don't worry, this process doesn't require any double clicks).
To change the settings on your mouse
Click Start, and then click My Computer.
Click Tools, and then click Folder Options.
Click Single-click to open an item. Then, click OK.
Now you can navigate folders and open files with a single rather than a double click. If you need to select a file, simply hold your mouse over the file for a few seconds without clicking.