The Windows and Mac versions do use different tools for converting and importing websites, so there will be some differences based on the platform. Even on a Windows system, factors like the network connection speed, available memory, etc. will affect this. Running Vista doesn’t necessarily mean you’ll have problems, but running Vista on a computer that’s been slowing down a lot lately probably would see issues.
Windows can import Wikipedia pages, but it’s still going to be down to the particular page, if there are elements that the converter isn’t able to process. It’s really down to the coding for the specific page, what sort of elements are on the page and how they’re embedded. Generally if you get an error importing the page, the solution is to try one of the other import converters, or if it’s a connection time-out, try again a little later; if none of that works, you’ll need to consider another method for bringing the webpage into Scrivener.
One option might be to print to PDF straight from the browser. Chrome offers this; I’m not sure if other browsers do. You may be able to install an add-on for that, or there are tools like the free CutePDF which give you the ability to print to PDF from any program. If that conversion to PDF works, you can then drag the PDF into Scrivener’s binder to import it.
You can also just try copying and pasting the webpage content, which will give you more control over what you’re including. You may end up running into an error with this, too, if there are elements on the page Scrivener isn’t able to copy (injected images usually), but by refining your selection you may get this working; for instance, try copying just the text. Pasting using Edit > Paste and Match Style may also work, as this pastes just plain-text. You can try saving the images from the page separately by right-clicking them, then inserting them into the Scrivener document by dragging them from your hard drive to the editor.
If having an archived copy of the page doesn’t matter, and the point is just to view it in Scrivener’s split editor rather than a separate browser window, the reference feature I mentioned earlier may work best for you. These are just links to the webpage, rather than a downloaded copy saved into the project. Select View > Inspect > References to switch to that pane in the inspector, and click in the “Document References” header to switch between the document references and the project references. Document references are specific to a single binder document, i.e. you have to select that document in order to see its references. Project references can be viewed no matter what documents are loaded in the editor.
Just drag the webpage URL from the browser address bar into the reference list to create a link, or use the “+” button to insert it. Then right-click the link and choose “Open in Editor” or “Open in Other Editor” to view the page directly in Scrivener. Double-clicking the icon will open the page in your default browser.
