Remaining number of installs

I bought the product NIS2012 licensed for 5 installs and have just installed it on 4 different computers over the last days, which give me the remaining last install. This last one is supposed to be installed on a laptop that isn't currently on site.

Today one PC is showing a error message 8506,422, whose instructions for fixing is to run Norton Removal Tools, download again the product from my Norton account and re-install it.

The question is whether doing this won't use the last available install leaving me with no means to install it on the 5th computer. 

Does anyone know how to re-install a product without loosing one allowed install?

Thanks.