TortoiseSVN is an easy-to-use version/source control client for Windows — it is developed under the GPL so it's completely free to use. TortoiseSVN is built on Subversion, a very popular open source version control system that is known for its reliability, scalability, and flexibility for enterprises of all sizes. You can use TortoiseSVN to access your Planio repository via your Windows PC and can also sync a local folder with your repository hosted on Planio.
Version Control for your PC
TortoiseSVN is a Windows-based Subversion client that features powerful commit capabilities, graphing, branch comparison, and conflict resolution. The robust Commit Dialog interface enables you to write log messages and discover local changes. Get a deeper view of data via TortoiseSVN’s visualization tools, such as revision graphs and project commit statistic graphs. There are also a number of useful tools, such as TortoiseMerge (for change and conflict resolution) and TortoiseIDiff (shows changes to image files).
Windows File Explorer Integration
TortoiseSVN integrates tightly into Explorer to create an easy-to-use interface for your day-to-day management of files and versions. All commands are available directly from the explorer—you can choose which options TortoiseSVN should show in both menus and sub-menus. Current file statuses, authors, and other SVN-specific columns can be easily included in your detailed explorer view. Also, files can be moved by simply right-dragging them from the explorer interface.
TortoiseSVN is open source. You can download it for free.