How to replace a wireless card in Dell Latitude E5430.

apart from needing the wifi password

open network sharing on the laptop
also
try trouble shoot problems

if no better
an ethernet cable is the next best testing tool

dell has a great thing , its called a service tag , all one needs to do is find service tag (sticker on case someplace) and go to dells web site with that number find service tags fixes and down load a new copy of the drivers to install

only dell can help with bios passwords

This password can be removed from BIOS, you should try to open BIOS (usually by pressing F2 during startup) and check if HD password is set.

it sounds like something was spilled on your keyboard, your gonna have to try to clean your keys by removing the key board. you can go here and follow how to do it http://www.manualslib.com/manual/414800/Dell-Latitude-E5430.html?page=15#manual

You can find a user manual: http://www.dell.com/support/Manuals/us/en/19/Product/latitude-e5430

http://search.dell.com/results.aspx?c=us&l=en&s=gen&cat=sup&k=Dell+latitude+120L&rpp=12&p=1&subcat=dyd%2f1005&rf=all&nk=f&sort=K&ira=False&~srd=False&ipsys=False&advsrch=False&~ck=anav
go here
download wireless drivers
Dell Wireless 1350 WLAN MiniPCI Card, Wireless 1450 WLAN miniPCI Card, Wireless 1350 WLAN PC Card, Wireless (Except US,Japan) WLAN Card, Wi... Download this driver if you reside outside the United States and Japan. This release supports the Dell Wireless 1350, 1370, 1450,1390, 1490, and 1500 series Mini Card, MiniPCI and PC Card devices (not USB). R140745.EXE Hard-Drive 52 MB Verify Operating System and Product Compatibility

what is your os?