OmniDiskSweeper is not available for Windows but there are plenty of alternatives that runs on Windows with similar functionality. The best Windows alternative is WinDirStat, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to OmniDiskSweeper and 15 are available for Windows so hopefully you can find a suitable replacement. Other interesting Windows alternatives to OmniDiskSweeper are WizTree (Free Personal), TreeSize (Paid), JDiskReport (Free) and SpaceMonger (Paid).
WizTree scans your entire hard drive and shows you which files and folders are using the most disk space. It does this VERY QUICKLY. In fact, we believe WizTree to be the fastest application of this type currently available!
TreeSize Professional tells you where precious disk space has gone to. It can be started from the context menu of a local folder or a local drive and displays the size of each folder, including its subfolders.
Free open-source cross-platform file & directory statistics as found on Github - Generate a directory tree for any given folder - View any folder as colored rectangles (squarified algorithm) - Customize the rectangle colors and show statistics about filetypes - Export...