The Wikipedia pages that could have additional information added to them are: http://en.wikipedia.org/wiki/Personal_computer_hardware and http://en.wikipedia.org/wiki/Electronic_waste.
On the first Wikipedia page, it gives information regarding the hardware in the personal computer. Although it is seen primarily in laptop computers, there is no information regarding the hardware for wireless communication. These may include the wireless cards and Bluetooth technologies. These are important because many devices nowadays are able to connect wirelessly. I believe the reason why this information is not on the webpage is that the hardware is not essential to the performance of a computer.
The second webpage is thorough with its content regarding electronic waste. However, one thing that might be nice to have on that webpage, in the section where the hazardous materials are listed, is the health problems related to that specific material/element entering into the environment and its respective health risks in people. I do see the point in not putting the health risks associated with each material on the Wikipedia page because it would clutter the webpage. If one does want to know the health risks, he or she only needs to click on the link to the material’s Wikipedia page where it provides information on the health risk.
Overall, I think the Wikipedia pages regarding e-waste, the PC, and the history of the development of the computer are extremely informative and include the information that a person using Wikipedia as a source would want to know.