I did some research on this recently. What I learned is that Ethanol is haram as it is "the type of alcohol found in alcoholic beverages." As for other alcohols, such as polyethylene glycol, while chemically they are alcohols, they are not intoxicants and hence not haram. Many pharmaceuticals, including muslim pharmaceuticals use polyethylene glycol in medicine excepeints. Note that for an alcohol to be haram, it has to be intoxicant.
Here's Wikipedia's defination of ethanol: Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. A psychoactive drug and one of the oldest recreational drugs known, ethanol produces a state known as alcohol intoxication when consumed. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a solvent, and as a fuel. In common usage, it is often referred to simply as alcohol or spirits.
So, yes ethanol is haram as it is an intoxicant. And so is ethyl alcohol.
See also:
http://en.wikipedia.org/wiki/Polyethylene_glycol
http://en.wikipedia.org/wiki/Ethanol