Hi
I have struggled with the period converter script and had given up on it, until a friend gave me this explaination.

Using the Period Converter script
-Get the 1 minute data from Alpari (M1)
-Delete all the .hst files of the currency pair you want to import from your
MetaTrader's history folder (for example C:\Program files/MetaTrader 4/history/InterbankFX Demo)
-In MT go to Tools -> Options and set max. bars in history and max. bars in chart to the
maximum by entering 99999999999 for each
-Go to Tools -> History Center and the currency pair you want to import and double click on M1. --Click on import and import the M1 data from Alpari that you just downloaded.
-Open a M1 chart of the currency pair
-Go to Tools -> History Center and the currency pair you want to import and double click on M1. Click on import
and import the M1 data from Alpari that you just downloaded.
-Drag the period converter script on to the chart and on the Inputs tab set the variable ExtPeriodMultiplier to 5 (for M5).
-After 30 sec or so doubleclick on the period_converter script in the MetaTrader Navigator window. This will stop the script the script and start it again. Click yes in the dialog box.
-Now start the script again and stop it after about 30 sec in the way described above with settings for ExtPeriodMultiplier of 15, 30, 60, 240 and 1440.
-Go to History Center, the currency you are importing, doubleclick on M5 and click on import. Now choose the path
C:\Program files/MetaTrader 4/history/InterbankFX Demo to import from and
there will be a file EURJPYM5 (if you are importing EURJPY) or similar, that the script just created.
Import from this file.
-Then go to M15 in the history center and import EURJPYM15 from C:\Program
files/MetaTrader 4/history/InterbankFX Demo
-Do the same for M30, H1 ... up tp D1
That's it