If you are talking about market replay data, you will only have that for the times your machine is running NT. Otherwise, Zenfire historical data comes from NT. What data feed are you using that you can't get historical data?
I am using NT with IB. was away for a week and would like to manually backtest my some ideas. The only data that loads is data from the times NT and IB was running. I wonder if I am doing something wrong or if there is a data provider that can help with historical range data or tick data to construct the range bars.
You are not doing anything wrong. Range bars are built from tick data and Interactive Brokers offers no historical tick data.
While you connect, you may opt to save the real-time data as historical data. But attention: the ticks supplied by Interactive Brokers are aggregated, so you do not get the ticks at full speed. This means that the ticks recorded from the real-time data are not those of the exchange, but far less. This also has some advantages, as you can run more indicators in CalculateOnBarClose = false mode without running into trouble. Each tick triggers OnBarUpdate(), and a reduced supply of ticks results in a reduced number of runs.
If you want historical tick data to test on range bars, you could try the Gain/Ninja Demo connection, which is free of charge. But you get what you pay for: low quality data. If you want to get quality tick data, you have to pay for it (for example e-Signal) or change your broker.