Thinking about an upgrade, is it difficult to install?

Take 20 seconds, undo one maybe three little screws, then pop the ram in and do the screws back up. job done

My next question is :), is this type of ram DDR2 PC2-4200, variable in type, or can I buy it from ebay or crucial memory and they will both fit and do the same job?

If that's the spec, then that's what you need. It is arguable that Crucial could be better quality though than some nondescript stuff from an unknown retailer.

Some laptops are trickier than others...some are a screw plate underneath the machine and it clips in - others can be keyboard out jobs...If your not sure for memory the crucial website will take you step by step through the process for your laptop and tell what you need and how much - I'm not sure if it also tells you how to fit it as well....

Yep, that's probably Crucials biggest selling point for non-experts - their Memory Assessment Tool.

crucial?

 

Corsair all the way :D