Long ago, in the days of DOS, there was no Registry where key system settings could be stored. And so variables such as, say, the location of the operating system Temporary folder were saved instead to the Environment, where they could freely accessed by all your programs.

These days the Environment is largely a relic of the past, but it can be useful to check its contents occasionally, if only as a part of cleaning up your system. And while you can do this within Windows (right-click Computer, click Properties > Advanced System Settings > Environment Variables), it’s generally much easier to use the free Rapid Environment Editor.

Launch the program as an administrator, if appropriate (right-click, select Run as Administrator) and you’ll see two groups of settings. The left-hand pane lists your System Variables, those which apply to the PC as a whole, while the right-hand User Variables pane lists everything that applies to your particular account.

Start just by browsing the list. You’ll probably find that several of your programs have created variables with a pointer to their installation folders (on our test PC these included Java, VirtualBox and SiSoft Sandra). If the variables disappear or become corrupted at some point then the applications may no longer work, so knowing which programs use the environment can be useful for troubleshooting purposes (or if you want to move a program folder without reinstalling, say).

Missing folders are highlighted in red, making it easy to spot path-related problems

And Rapid Environment Editor will try to alert you to issues by highlighting “broken” environment variables in red. On our test system, for instance, the System Path (a list of locations where Windows will search for executable files) was highlighted. And sure enough. expanding the tree revealed two copies of “C:\Program Files (x86)\Common Files\Roxio Shared\DLLShared\” in the list, which no longer existed as we’d uninstalled the Roxio software.

If you similarly find path variables which you’re 100% sure are safe to remove, click File > Backup to save a copy of your original environment first, just in case, then right-click each variable in question and select Delete. And the shorter path will then reduce the work Windows has to do when searching for executable files, though only fractionally (there almost certainly won’t be any measurable difference).

Rapid Environment Editor can help you clean up your system in other ways, though. Scan down the list of Path folders, and you may find some for tools which you know you’ve uninstalled, but aren’t highlighted in red, and this means those folders are still present on your PC.

On our test system, for instance, the system path included “C:\Program Files (x86)\Common Files\Roxio Shared\13.0\DLLShared\”, which wasn’t highlighted, and that meant the folder had been left behind when we uninstalled a previous Roxio trial. Checking the folder revealed it contained only a “roxio_lvm.log” file, so we knew it was safe to erase, before moving on to delete the Path variable as well.

Of course as optimisations go these are all very minor, and Rapid Environment Editor won’t exactly be replacing CCleaner any time soon. The program can help you to identify configuration issues which aren’t otherwise easy to spot, though, and so it’s a good idea to keep a copy around, if only for very occasional use.