I find it amazing that this isn't simply part of Windows by now. The operating system has had a default mail client setting for a very long time, and Web-based email isn't exactly a new idea, either. Yet Microsoft has never added a way to make that mail client a URL rather than a program.
So we have to use third-party software to work around Windows' limitations.
In this post, I'm going to concentrate on browser-based fixes. These work for the mailto links on web pages (such as answer@pcworld.com), but don't help if you want to send mail from Windows Explorer, Word, or other applications. I'll continue with those in Monday's post.
Firefox has one such tool built in--at least if you're using Gmail or Yahoo Mail. Select Tools, then Options. Click the Applications tab. Select mailto, pull down the menu, and select Use Gmail or Use Yahoo! Mail.

Chrome users should go to the Chrome web store and
search for mailto. You'll find plenty of Mail plug-ins for specific services. You'll also find the generic
Mailto, which supports AOL, Fastmail, Gmail, Hotmail, Yahoo, Zoho, or, with a bit of work, other services.
I know of no such add-ins for Internet Explorer. However, the two Gmail-specific solutions I discuss below, plus the one on Monday, will work with Microsoft's browser.
If you use Gmail, Google offers two free programs, either of which will handle mailto links appropriately:
Gmail Notifierand the
Google Toolbar. Both of these have other features and come with other baggage, so you may or may not want them.
If you decide to install the Notifier, make sure to leave the Use for outgoing mail option checked. If you go with the Toolbar, click the Tool icon, and in the General tab, check Use Gmail for "Mail To" links.

Windows has had a handy Default Mail Client setting for a very long time. It not only allows you to click a mailto link in your browser and go directly to your email program of choice, but it also lets you to mail a document directly from Word, an archive from WinZip, and any file from Windows Explorer.
Clicking the E-mail button in Windows ExplorerUnless you're using a Web-based mail service like Gmail or Hotmail. Then, it seems, you're out of luck. You can't enter a URL as your default mail client.
Now here's a solution that will work with everything else (and work with those mailto links, as well).
The solution is a little program called
Affixa. It's free, but you can get more features for an annual subscription of only ₤2 ($3.11 as I write this).
Affixa installs into Windows as your default mail program and supports Gmail, Yahoo! Mail, Google Apps, Zimbra and the Outlook Web App. When you tell a program that you want to mail something, Affixa redirects your request to your Web-based mail service.

These tips will make it work better:
1. In Affixa's Options dialog box, click the Options tab, and uncheck Load Affixa on Startup. You don't need it running at all times.
2. When setting up your account, click the Preferences tab, and in the 'After creating a draft message' pull-down menu, select Show in web browser. That way, your new message will come up automatically.

3. Although Affixa works with mailto links in your browser, it's slower here than the Firefox- and Chrome-based solutions discussed earlier. I recommend that Firefox and Chrome users install both. The browser-based solutions will work with Web page mailto links, and Affixa will work with everything else.