View and import REG files safely with RegMerge

.REG files are a quick way of making multiple changes to the Windows Registry. Double-click one, REGEDIT asks if you’d like to apply its tweaks, and once you’ve said "yes" it'll update every key in the file.

Fast? Yes. Convenient? Certainly. But what if you don’t really want to make perhaps hundreds of Registry changes without having the slightest idea of what they’re doing?

Bitsum Technology’s RegMerge is a free tool which helps out by displaying the contents of the REG file first, highlighting differences from your current settings, and allowing you to choose which, if any of the changes to apply.

The program is a tiny 173KB download which installed without hassle on our test PC.

By default RegMerge sets itself up as the handler for REG files, ensuring it'll be called up if you -- or any application -- launches one in future. That seems like a sensible security move to us, but you can choose to keep your existing REG handler, if you prefer.

Open any REG file and RegMerge displays a table listing the details of each setting: Hive, Key, Value Name, Value Type, and the value to be set.

A "Compare" column shows how each REG entry might change your existing settings. If you scroll down the list and every setting says "Missing", for instance, that means your Registry doesn’t have any of the keys in the file. "Invert" means a setting has been toggled, "Changed" means it’s different in some other way, and so on.

This makes RegMerge useful as a REG file viewer. You don't have to read every line of technical text to get a general idea of what a file is going to do: just scan the "Compare" column and you'll immediately see whether there are lots of changes, or it's mostly just adding new keys.

If the file appears safe and you’re happy to make its changes, select Check > All > Apply, click Merge and your Registry will be updated accordingly.

RegMerge also enables you to be selective. Clear the checkbox next to any entry you’d like to avoid and it won't be applied.

Alternatively, a filter option allows you to make more global choices. Check and merge only the "Missing" items and RegMerge will apply only the Registry keys you don’t have already, for example -- everything else will remain unchanged.

There are interface issues with all of this, probably because RegMerge is a very early alpha build. There's no drag and drop support, the table can take ages to update with large REG files, and there are no handy right-click menu options to do anything smart with the selected files.

The core of the program works well, though, and we'll be interested to see how it develops.

RegMerge is a free tool for Windows 7 and later.