Tried with Windows 7, I get a yellow exclamation mark in Device Manager. If you go to the Prolific brand website (which this cable claims to be) it says that knock off bootleg cables give the yellow exclamation mark.
I have another Prolific USB to RS232 cable that works fine with the same laptop, but this was from a more reputable dealer.
If I could give 0 stars I would.
As this was such a cheap cable its not worth returning it as postage would be more than the cost of the item, a total rip off product.