# RegWriteULong

int RegWriteULong (unsigned int rootKey, const char subkeyName[], const char valueName[], unsigned long dataValue, int dataFormat);

## Purpose

This function writes an unsigned long (DWORD) value to the Windows Registry. You must specify a Root Key, a Subkey of that Root Key, and the actual Value of that Subkey to which you want to write the data.

Example:

unsigned int number = 10;
// Writes 10 in Little–Endian format in MyULongValue
RegWriteULong (REGKEY_HKLM, "Software\\MySubKey",
"MyULongValue", number, 0);

## Parameters

Input
Name | Type | Description
rootKey | unsigned integer | The Root Key under which you wish to access a Subkey and its value. See the Windows Registry functions Class help for more information on Root Keys.
subkeyName | const char [] | The name of the Subkey (relative to the Root Key), to which you want to write value data. See the Windows Registry functions Class help for more information on Subkeys.
valueName | const char [] | The name of the value to which you want to write data. If the value name does not exist this function will create it. See the Windows Registry functions Class help for more information on Key Values.
dataValue | unsigned long | The data you wish to write to the specified Value of the specified Subkey.
dataFormat | integer | This parameter controls how the 32–bit integer should be writen to the Registry. Typically, you will specify Little–Endian (Intel) format.

## Return Value

Name | Type | Description
status | integer | The status code that the function returns. 0 indicates success. A negative value indicates an error. This function may return a Programmer's Toolbox or UI Library error code. Call GetGeneralErrorString to obtain a text description of the error.