Method Combining Landsat Bands in ER Mapper

When purchasing or acquiring the satellite image data often not incorporated and each band is still in a state separate. For example, Landsat 5 TM is separated into seven bands in GeoTiff format or img.
By combining them?

Open the first band to merge, copy pseudolayer by clicking on the icon copy and paste, rename it to band 1, 2, 3, 4, 5 and 7.
It fits each band with a tiff file on preliminary data, the opening through the layer on the algorithm> point on the band in question> Do not click OK select the This Layer Only.
Click the Edit icon Transform Limit> Choose Default Linear Transform> Limits> Limit To Actual.
Save as data in ER Mapper Raster Dataset format or. Ers in a format and save it as well. ALG