Storing data

Hey guys, i just have a quick question about storing a large amount of data. I will be allowing users to add lets say a Company, each company will have a code, name, contact and email contact. Now i know i can store all this data with Xml Serialization and de-serialize a specific node that i need, but someone said that it might be better to use a access data base for fast access and it might use less resources. So im kinda stuck on which way to go, any suggestions would be great.

thank you,
Wes