Generally speaking, clicking OK on a dialog box like that in a webpage will not let the website actually download any files to your computer. That dialog is a JavaScript Alert dialog, and is in and of itself harmless - I wouldn't call it a "hack" per se. It is possible that after clicking OK, the page might redirect to a download, but cicking ok would not in and of itself cause an infection, unless there were already malicious scripts on the page, in which case, you'd already have been infected.
That being said, this is still a sleazy tactic to use on the web, and is a good example of a misleading UI designed to confuse users into downloading software they may not want. It sounds like this may not actually be a malware site, but for future reference for other sites, you can report badware to various groups such as Google and Microsoft, and they can place the site on the block lists for their browsers. See "how to report a malicious website" for more info on that.
If a website is showing incessant alert dialogs, some browsers will allow you to check a box asking not to show any more alerts from that site. I know Chrome has this capability, and gives you the option after more than 2 dialogs are shown in a row. I'm not sure if Safari does or not.
Some companies use nefarious SEO tactics and flood online review sites with fake positive comments; some will even hire people to write positive reviews for the. I don't know if the company in question is doing this or not, but it is one possibility.
Best Answer
Most likely (but untested here) reason is that the folder is being guarded/accessed is its designation as a profile folder. The tutorial from TenForums edits the
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\<*User SID*>path before renaming the folder.