Dell Inspiron 5100 - Manual (Page 73)

Setting Up a Home and Office Network 73
4 From the Data encryption drop-down menu, select your data encryption type
(as provided by the network administrator).
5 If your wireless network requires a key, enter it in the Network key field.
6 Click OK.]
Your network setup is complete.
NOTE: Your computer may take up to a minute to attach to the network.
Connecting to a Network With Wired Equivalent Protocol (WEP) Security Requirements
1 In the Preferred networks section, click the name of your wireless network.
2 Click Properties.