The first thing I'd want to know is the exact make and model of the laptop, VGA to HDMI is not a standard lead, and shouldn't work as VGA is an analogue signal, HDMI is digital. if that lead came with the laptop then it may be that the VGA output can be switched to be digital and therefore compatible with HDMI, If this is the case then it's not a standard scenario and is specific to that laptop
assuming that the lead came with the laptop and therefore should work then as Vagrant indicated on the previous thread you will need to switch on the VGA output as it's not enabled by default. again how this is done varies depending on make and model of laptop.
Some can be switched on by simply hitting a combination of the FN key (the FN key only exists on laptop keyboards) and one of the function keys, so look for extra markings on one of the F keys.
If you can't switch it on like that then almost all laptops will have an icon down near the clock for changing the graphics settings and multi-monitor supports can be switched on somewhere in there, if you hoover the mouse pointer over the icons it will tell you what they are, you are looking for either "intel graphics driver", "ATI catalyst control centre" or "Nvidea control centre" depending on the graphics chip in the laptop.
If you can provide the make and model of the laptop I can be more precise with the instructions.