Rezising Zenworks Partition

Hello all, here's the scenario:

I have created an image for IBM laptops that will work with most models that we have such as A series, R series and T series.

When I load the image onto the T series like the T42, the image works, however the partition size on the disk is only 20gig whereas the actual size of the HDD on the T42 is 80gig. Does anyone knows how to manually change Zenworks 4 to detect the size of the destination drive and use that when installing the image?

Thanks in advance