Dell Latitude E5520M (Early 2011) - Manual (Page 6)

4
Battery Slice
3 Before you undock your computer, set your computer’s power
management settings so that it does not enter sleep, standby, or hibernate
mode when you close (lower) the display:
Windows 7:
a Click Start → Control Panel→ Hardware and Sound→ Power
Options → Change what closing the lid does.
b Under the When I close the lid drop-down menu, select Do nothing.
Windows Vista:
a Click Start → Control Panel→ Mobile PC→ Power Options→
Change what closing the lid does.
b Under the When I close the lid drop-down menu, select Do nothing.
Windows XP:
a Click Start → Control Panel→ Performance and Maintenance→
Power Options → Advanced.
b Under the When I close the lid drop-down menu, select Do nothing.
Docking Your Computer to the Battery Slice
1 Follow the procedures in "Setting up Your Battery Slice" on page 3.
2 Turn over the computer and lower the battery slice until it clicks into place.
3 Flip the computer and power it ON.