Laptops usually run on ram called so-dimm. Its a differnet shape to normal ram and is upgraded usually by a flap on the bottom of the laptop. Heres a example of what so-dimm looks like:
Now chances are, youll either be using SD-RAM or DDR Ram. If you can post what motherboard you have that will help alot. Since your buying that much ram you really have to know what type and speed of ram, and only some higher end motherboards support 4gb of ram.
This is what SDRAM looks like:
Note there is 2 notches on the bottom of the module.
The other common type of ram is the Newer and Faster DDR Ram.
This is what DDR Ram looks like:
Note the only one notch.
If you can post your motherboard model, we can tell what ram you can have and point you in the right direction.
what do you need 4 gig's of ram for? That is nothing but a waste of money big time,The only thing i ever seen actually running 4 gig's was a dual xeon NAS server with about 16 250gig hard drive's used for huge a$$ company's.
oh well, im still not going to upgrade for a while (need $$$).
The admin at my school is going to upgrade all the computers to xp. That means he has to upgrade all the ram from 64 to 128 to comply with the MINIMUM requirements for xp. No wonder the computers at school always run slowly.