Thanks for the help. I solved my issue with the following code:
string[] contenutoStorico = rigaStorico.Select(x => x.Name).ToArray();
IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication();
using (StreamWriter writeFile = new StreamWriter(new IsolatedStorageFileStream("history.txt", FileMode.Create, FileAccess.Write, myIsolatedStorage)))
{
for (int i = 0; i < contenutoStorico.Length; i++)
{
writeFile.WriteLine(contenutoStorico[contenutoStorico.Length-i-1]);
}
writeFile.Close();
}