Windows stores a lot of critical information in the registry, which is loaded (at least a part of it) during an early stage while booting. If you remove this information Windows will be unable to find and load critical system files and thus be unable to boot.
Such critical information is e.g. the list of device drivers needed for booting the system. This may include:
- disk drivers (floppies, hard disks, CDs, USB-devices, ...)
- bus drivers (IDE, SATA AHCI, ...)
- file system drivers (FAT, NTFS, ...)
However, by default Windows stores a backup copy of the registry. If you've enabled "System Restore" you can find such copies in the (hidden)
System Volume Information Folder inside the root folder of the system partition. Additionally, even if you do not have "System Restore" enabled, Windows saves a backup copy of the registry in
You can manually copy the backup files into
%WINDIR%\System32\config\ to restore the registry data.