Depends entirely on what cookies they use. If they only set cookies from their own domain (first-party cookies), they might be able to know that you visited their site before, but it wouldn't tell them anything about third party websites, in general.
If they set cookies from other sites (third party cookies), the third party might be able to tell that you have visited example.com, example.org, and example.net - but only if all of these sites include third party cookies from the same provider. Example.com wouldn't be able to tell that you'd also visited example.org, unless the third party told them (perhaps through an online dashboard), or you followed a link from example.org to example.com, and your browser set the "referrer" header when connecting.
Most third party cookies belong to large advertising companies, such as Google or Facebook, or to social network companies, such as Twitter or Facebook. Because these companies are included on a lot of sites for various reasons (enabling sharing functions, analytics monitoring, embedded feeds of data), they can easily build up a picture of where you have been.
When you opt out of tracking (the "do not track" option) on any of these sites, it just sets another cookie which tells them not to link any data about your online behaviour together.
Your ISP knows what sites you visit through different means - your data passes through their systems, so they can just grab out a list of where you have been. Depending on your country, it might be a legal requirement for them to store this data.
Your PC manufacturer, though, probably can't tell what websites you've been on, unless they pre-installed some tracking software (look up "Lenovo superfish" for an example of this), but this is not particularly common, since it causes all kinds of bad publicity for them, and doesn't provide them with any useful information.