Can websites record my pc's "id number"?

[RCN]

I was wondering if my pc gives off an ID number each time I visit a website? After visiting a specific site a few times, it suddenly became unaccessible as it then required I sign up, etc.

Is there any software that can prevent sites from knowing when I visit their site?

I'm still a newbie, so any answers in layman's term would be greatly appreciated!

[Miz]

A computer can only display data that's on its own harddrive. When you visit a website, the server where the website is located must send the data to your computer. To do that, the server must know your computer's "address." Every computer online has a unique addres called an IP. Therefore, your computer transmits its IP address so the server will know where to send the data.

When you access a site that requires you to log in (that is, set up an account with a user name and password) or on which you personalize the page, it wil place a "cookie" on your computer. It's a tiny file that identifies your computer so that the next time you access that site, it recognizes your computer.

If I'm understanding the problem with the one particular website, it apparently only lets you visit it a few times before you're required to set up an account. It uses a cookie to identify your computer.

Cookies from reputable sites do not collect personal information. They don't know your name, address, telephone number, credit card number, email address or any other personal information. They just identify your computer as one that's been there before. If, of course, you've given the web site any personal information, it will be stored on the web site's server and identified as belonging to your computer through that cookie.

"Tracking cookies," on the other hand, will track where your computer goes online and send that information back to its owners. Tracking cookies are mainly used to identify your computer's surfing habits so advertisers can target it with specific ads. For example, if your computer goes to several websites looking at kitchen appliances, you will start to notice that you're seeing ads on different web sites for kitchen applicances.

To forestall most tracking cookies from being placed on your computer and if you use Internet Explorer, in IE go to Tools>Internet Options>Privacy tab>Advanced button, check the box for "Override automatic cookie handling" then check "Block" under "Third party cookies," and the one for "Always allow session cookies," click OK and OK again.

If you're surfing dodgy sites...for example, warez or porn...all sorts of things, usually bad, can be put on your computer without your knowledge.

The way to surf the web anonymously is to go through a proxy server. A Google search for "proxy server" will give you plenty of resources to start learning how to do that. They're more trouble than they're worth, in my opinion, and generally slow your surfing down noticeably.

[degsy]

If it popup up a warning saying that you have visited too many times then it is probably recording your IP address access.

This could be a false action because you could be sharing the IP Address with your neighbourhood or area if your ISP is using a cache/proxy server.

[Tristansdaz]

I've also noted a dramatic decrease in popups and such using GhostSurfPro. It seems to work with no problems for me, never know it's there and working. Just 2 cents worth.

[RCN]

Thanks to everybody for all the advice!!