Solved issue about sharp AR M-236 in Windows 8. I've been trying to connect to a shared printer on an OS running on Windows XP. No drivers were given for Winows 8. The first thing to do is disabling driver signature in Windows 8 that is given as default:
Disable Driver Signature Verification

Then you have to install the driver (depending on 64-bit or 32-bit architecture):

During installation you will be asked to specify whether the printer is shared or directly connected. Choose shared and then specify the canonical windows path, for example:

where John is the computer where the copier Sharp Ar-m236 is installed and working...

Hope it helps