Normally the hidden adminstrator account is used for "Last minute resort" on safe mode.

Try Creating a Administrative Account. If it was a brand new computer with vista - it normally goes through step 2 of setting up the main account and choose the name , password etc. This is account you use to start from. Try Setting Up a Administrive Account From Within the hidden account.

Make Sure You have all the Windows & Microsoft Updates, JAVA Updated & Flash. Try Installing Itunes. Also Try Saving The File , Right Click on it and select "Run As Administrator".