Registry element size limits
The following table identifies the size limits for the various registry elements.
For an explanation of standard and latest formats, see Registry files.
|Registry element||Size limit|
|Key name||255 characters. The key name includes the absolute path of the key in the registry, always starting at a base key, for example, HKEY_LOCAL_MACHINE.|
|Value name||16,383 characters. Windows 2000: 260 ANSI characters or 16,383 Unicode characters.|
|Value||Available memory (latest format) 1 MB (standard format)|
|Tree||A registry tree can be 512 levels deep. You can create up to 32 levels at a time through a single registry API call.|
Long values (more than 2,048 bytes) should be stored in a file, and the location of the file should be stored in the registry. This helps the registry to perform efficiently.
The file location can be the name of a value or the data of a value. Each backslash in the location string must be preceded by another backslash as an escape character. For example, specify "C:\\mydir\\myfile" to store the string "C:\mydir\myfile". A file location can also be the name of a key if it is within the 255-character limit for key names and does not contain backslashes, which are not allowed in key names.