Hi All I am new to the forum. i am a electronics troubleshooter for a uk company,specialising in power supplies and led lighting control.One of the regular transistors i use is the good old LM317. I have an EXCEL file to calculate R1 and R2.You can either key in the voltage you require and one of the resistor values or both resistor values and it will tell you the voltage you will get. The problem is either i am being thick of it's this b****y vista but it will not let me import it into a thread. If anybody can help me i will import it as i think there will be members that will find it useful.