A formatted VHD can be concerning because formatting may remove the file-system information needed to access the original data. This can happen when a virtual machine is recreated, a virtual disk is accidentally formatted, or an administrator initializes the wrong virtual disk.

The first thing to remember is not to overwrite the VHD with new data. Any new activity on the virtual disk can potentially affect the recoverable information. If the data is important, keep the original VHD untouched and work from a copy whenever possible.

Recovery also depends on the structure of the virtual disk. A VHD may use a fixed or dynamically expanding format, and its partitions can use MBR or GPT. The file system inside the virtual disk is another factor. Different recovery situations may require different scanning approaches.

SysInfo VHD Recovery Tool supports both fixed and dynamic VHD files and provides recovery options for MBR and GPT partitioning. It also lists support for file systems including NTFS, FAT16, FAT32, FAT64, HFS+, EXT and RAW.

One useful feature is the ability to perform Standard or Advanced scanning. The Advanced scan provides additional settings, including custom start and end sectors, which can be useful when a normal scan doesn't locate the required volume correctly. The software also provides Standard, Advanced, and Deep recovery modes.

Another important step is previewing the results before saving anything. The tool displays recovered folders and files in a tree hierarchy and allows individual items to be previewed. This makes it possible to identify the data you actually need rather than blindly restoring everything.

The software also provides an option to save the recovered VHD disk image to a specified location. This can be useful when the objective is to preserve the recovered virtual-disk structure for further work.

However, recovery isn't guaranteed for every formatted virtual disk. The final result depends on factors such as how the VHD was formatted, whether new data has overwritten the previous content, and the condition of the underlying file system.

So, if a VHD has been accidentally formatted, avoid further writes, preserve the original file, scan it using an appropriate recovery method, and preview the results before saving the recovered data.