To search part of the registry, use the following syntax:
REG Query HKxx\subkey [/D|/K|/V] /F "search_pattern" /S [/E] [/C]
To search an entire registry hive, just omit the subkey:
REG Query HKxx [/D|/K|/V] /F "search_pattern" /S [/E] [/C]
Use /D to search the data (i.e. the registry values' values), /K to search for matching key names, /V to search for matching value names, or none of these switches to search keys, values and data.
Searches with /K or /V are fast, searches with /D or none of these switches are slow.
So make sure to use /K or /V if you do not need to search the registry data.
Hover your mouse pointer over the image to display the names of components.
Use /C for cases sensitive searches, and /E for exact matches only (no partial matches).
My guess is that using /E and /C would make searches a fraction faster, especially when searching registry data.