Networks, Internet, USB, wifi, Bluetooth, CD, DVD, Blu-ray– modern PCs make it easy to exchange files with the outside world.

Sounds great. Unless you’re running a business, perhaps managing several PCs, each packed with confidential files which you don’t want copied or shared without permission.

GiliSoft USB Lock ($39.95 right now for a lifetime license, $49.95 normally) provides a range of ways to lock down your PC, and limit unauthorised data leakage.

As you’ll guess from the name, this starts by preventing users writing to USB disks, maybe reading them as well (bonus points for virus protection).

Too restrictive? You’re able to create a whitelist of your own USB disks. These will be recognised and work as normal, everything else gets blocked.

Most features can be toggled on or off by clicking a checkbox

The program can also prevent users writing to USB disks, or burning CDs/ DVDs, as well as disabling SD Card Readers and blocking connections to Android and iPhone devices.

There are other ways to transfer data, of course, but GiliSoft USB Lock can block most of those with a click: printers, modems, COM/ LPT, infrared, Bluetooth, Firewire/ 1394.

That blocks most local opportunities for data copying, but if the user can get online, they may be able to upload files to some cloud location for easier access later.

GiliSoft USB Lock can help out by restricting web access to specific websites only. Or if that’s not enough, it’s even possible to disable your network adapters.

If a snooper can’t find his way around these blocks, he might try to remove GiliSoft USB Lock’s protection, but that’s not easy. You can’t uninstall the program or change its settings without entering a password, and options to disable Task Manager, REGEDIT, and Remote Desktop Connection also reduce any attacker’s options.

Heavy-duty restrictions like blocking web or network access won’t be for everyone, and even they can’t offer complete security. If a file can be displayed or scrolled on screen, then someone could always photograph or film it.

Still, if you really need this level of protection, then GiliSoft USB Lock’s multi-layered approach is more effective than most. It’s also on offer at the moment, $49.95 lifetime/ 1PC, $99.95 lifetime/ 3 PCs, so grab a copy now if you’re interested.

GiliSoft USB Lock is a commercial application for Windows 2000 and later.