E520 memory not recognized

[craigbwalter]

I have a Dell E520. I have 1GB memory sims in slots 1&2. Now I add two more 1GB memory sims in slots 3&4 but they are not recognized. When I enter the bios it just says nothing is in those slots and that memory configuration through the bios is unchangeable.

I have seen other people say that have this same problem, but I have not seen anyone provide a solution.

 

[GhislainG]

Are the new modules certified to work in that system? Do they work in the first 2 slots?