What else can I do ?

My 30day trial period for win4utomation just expired. Any ideas on how can I make it to work again for another 30 ? I've uninstalled it with revo, manually searched and deleted some registry entries related to the software, restarted PC, changed MAC address installed it again but still no luck. I keep getting the "Evaluation period expired" message ?
Where and what kind of files should I look for to delete in order to make it work again ?

it might be the volume ID of your hard drive.
it can be change with certain programs like the tool from systernals
check this article for more information http://www.raymond.cc/blog/changing-or-spoofing-hard-disk-hardware-serial-number-and-volume-id/

Or just install vm