Gerando Números Aleatórios e Strings em C #

//RANDOM STRING
string random = System.IO.Path.GetRandomFileName().Replace(".", string.Empty);

//RANDOM PASSWORD/STRING
string randomPass = System.Web.Security.Membership.GeneratePassword(10, 0);

//RANDOM INT
System.Random randomInt = new System.Random((int)System.DateTime.Now.Ticks);
int start = 1;
int size = 1000;
int result= randomInt.Next(start, size);

source: http://blog.codeeffects.com/Article/Generate-Random-Numbers-And-Strings-C-Sharp