ReadyBoost improves your system performance by using faster USB Flash Drives instead of slower hard disks for system operations. It works best using flash drives with at least 1 GB of storage.
Simply insert your flash drive, and if it meets certain performance benchmarks, Windows 7 will ask you if you want to use it for ReadyBoost and recommend the size to reserve.
You can lock your computer using the Windows Key +L keyboard shortcut.
Here’s another way to do it with a single mouse click. Right-click on your desktop, select New, Shortcut. In Type the location of the item, enter
rundll32.exe user32.dll,LockWorkStation
Click Next, name the shortcut ‘Quick Lock’, and Finish.
If you wish, you can make it look pretty by giving it a lock or keys icon:
Right-click, select Properties, click Change Icon, enter shell32.dll, and select any icon you wish. Drag this shortcut and pin it to the taskbar, after which you can delete the desktop shortcut.