EDIT: Me == Comprehension Fail Thanks for corrections below.

I didn't realise that. The previous version I had - the on that had "Generate Coins" in a menu used the CPU to mine.

If the current Windows version really does use the GPU to mine, then why should I be using CGMiner? (Can't test at the moment due to PSU issue.) http://www.weusecoins.com/mining-guide.php seems to imply that GPU mining is not native to the Windows Bitcoin Application. Likewise, https://en.bitcoin.it/wiki/FAQ#Why_was_the_.22Generate_coin.22_option_of_the_client_software_removed.3F makes no mention of this capability.