what kind of battery do i need to replace my laptop battery for IBM ThinkPad? It wont charge and i reckon its because of the battery

my ibm thinkpad t42 type 2373 only types numbers on the keyboard i need help because i need to type letters not numbers. thank you!

i know exactly what the prob is, its the dust and crap in the fan, but how do i go about opening my laptop to clean it, i know to remove the lid on the bottom and all screws, then pop the top of the keyboard off then rmove those screws but now what? i need help. . . the laptop is a Toshiba Satellite a215 s7422, the fans have completly stopped spinning. . . . so it burns the crap outta my leg, and shuts off due to overheating

Ok im looking for a cheap simple to use laptop or desktop. I basicaly only need to; Upload and edit photos, play music, have word(school), and enough internet to check yahoo and a few other things. But other than that i dont need a huge,fancy,tons of feactuers desktop or laptop. Any thoughts please help.

I am using a generic driver w/allows internet access but the wlan driver is the last one I need to bring my pc back to its original state.
So far I see this under specs: Acer InviLink 802. 11b/g wireless LAN driver aspire 4520, but I don’t know where the driver d/l is located.