Database Issue...

Question

Hi Here´s the problem... Im creating a windows application in c#.net (studio 20003) and the application is meant to work with one PC. 1.- The application will store data so, so i whant to know what will be the best database for this type of application (1PC, no-network, no sharing). 2.-if i use sql , when i decide to install the program in another machine, will I have to install sql server there? 3.-Can I use XML? Thanx, i will appreciate any help