It’s easy to customise the shortcut icon for a Windows application, at least in theory: just right-click it, select Change Icon, and choose whatever icon you’d prefer.

Of course you have to find a suitable icon, first, and that’s where life gets a little more difficult. Windows actually provides thousands of icons you could use, but tracking them down isn’t easy – unless you get help from a third-party tool like Icon Explorer.

The program is straightforward to use. It’s portable, so there’s no need to install it: just unzip the download file, launch IconExplorer.exe, and point the program at a folder you’d like to examine. (\Windows\System32, or the equivalent folder on your system, is a good place to start looking if you’re short on ideas.)

As soon as you’ve selected a folder, Icon Explorer will scan its contents, checking each file for icons. And on completion, you’ll see a list of file names and the total number of icons each one contains.

The results can be a real surprise. We already knew that Shell32.dll contained many icons, for instance – 306 on our test Windows 7 system – but we hadn’t realised that there were so many others, more than 4,200 in the Windows\System32 folder alone on our trial PC.

Imageres.dll and DDORes.dll are particularly good examples on Windows 7, providing 300 icons between them, each available in a range of resolutions (16×16 up to 256×256). Just click on either file to see thumbnails of everything it contains, and selecting any one of these will display the full-sized icons. (Right-click one to export it as an individual icon or bitmap image.)

And so if you’d to customise a shortcut icon, then right-click it, select Properties > Change Icon, click Browse and choose your preferred icon-packed file; \Windows\System32\Imageres.dll, say. Select whatever icon you’d like to use, click OK, and that’s it, your shortcut should be updated right away.

If you’re searching for hi-res icons elsewhere then Icon Explorer may not be quite so convenient, as it has no way to filter its display by icon size. It’s still a handy tool, though, compact, free and exceptionally portable (the authors say it should run on any version of Windows from 95 upwards), so if you can live with the search limitations then you’ll probably find it very useful.