Identifiably information about my pc?

There is a website where I can order free coupons for a local service.
The website only seems to accept * coupon order per pc.
The website seems to be able to identify a pc that has previously visited the website.

I took these steps:
- deleted all cookies in Firefox
- changed my IP address by using TOR

If I try to order again using my own pc, the order is not accepted
If I try to order again using another pc, the order is accepted

Am I overlooking something that is disclosing identifiably information about my pc?

Thanks,
Vinny

vinny, google for a program named ccleaner, it's free. Run the cleaner and then run the registry tool. That may do it. If not, at least your comp should run a little faster.

Try after you disable java,wich is what's enabling to fingerprint your pc. Also if interested there is a free proxy called hotspotshield,it is add based but works pretty good.

Good to see you again Gordo,hope everything is going ok for you my friend.

Hi Noz, thanks for the input.