в реестре

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders

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Platform SDK: Windows System Information
Getting System Information
The following example uses the GetComputerName, GetUserName, GetSystemDirectory, GetWindowsDirectory, and ExpandEnvironmentStrings functions to get information that describes the system configuration. This example displays the information in a window's client area.

LPTSTR lpszSystemInfo; // pointer to system information string
DWORD cchBuff = 256; // size of computer or user name
TCHAR tchBuffer2[BUFFER]; // buffer for concatenated string

DWORD dwResult; // function return value

SYSTEM_INFO siSysInfo; // structure for hardware information
int aTabs = {260}; // tab stop for TabbedTextOut

TCHAR tchBuffer[BUFFER]; // buffer for expanded string
int nSize; // size of string

lpszSystemInfo = tchBuffer2;

// Get and display the name of the computer.

GetComputerName(lpszSystemInfo, &cchBuff);

nSize = sprintf(tchBuffer, "Computer name: %s",
lpszSystemInfo);
TextOut(hdc, 15, 20, tchBuffer, nSize);

// Get and display the user name.

GetUserName(lpszSystemInfo, &cchBuff);

nSize = sprintf(tchBuffer, "User name: %s",
lpszSystemInfo);
TextOut(hdc, 15, 40, tchBuffer, nSize);

// Get and display the system directory.

nSize = GetSystemDirectory(lpszSystemInfo, MAX_PATH+1);

nSize = sprintf(tchBuffer, "System directory: %s",
lpszSystemInfo);
TextOut(hdc, 15, 60, tchBuffer, nSize);

// Get and display the Windows directory.

nSize = GetWindowsDirectory(lpszSystemInfo, MAX_PATH+1);

nSize = sprintf(tchBuffer, "Windows directory: %s",
lpszSystemInfo);
TextOut(hdc, 15, 80, tchBuffer, nSize);

// Display the "environment variables" header.

nSize = sprintf(tchBuffer,
"Environment variables (partial list):");
TextOut(hdc, 15, 105, tchBuffer, nSize);

// Expand the OS and NTVERSION environment variables.

dwResult = ExpandEnvironmentStrings(
"OS=%OS% NTVERSION=%NTVERSION%",
lpszSystemInfo,
BUFFER);

TextOut(hdc, 25, 120, (LPCTSTR) lpszSystemInfo,
dwResult - 1);

// Expand the PATH environment variable.

dwResult = ExpandEnvironmentStrings(
"PATH=%PATH%",
lpszSystemInfo,
BUFFER);

TextOut(hdc, 25, 135, (LPCTSTR) lpszSystemInfo,
dwResult - 1);

// Expand the LIBPATH environment variable.

dwResult = ExpandEnvironmentStrings(
"LIBPATH=%LIBPATH%",
lpszSystemInfo,
BUFFER);

TextOut(hdc, 25, 150, (LPCTSTR) lpszSystemInfo,
dwResult - 1);

// Expand the TMP environment variable.

dwResult = ExpandEnvironmentStrings(
"TMP=%TMP%",
lpszSystemInfo,
BUFFER);

TextOut(hdc, 25, 165, (LPCTSTR) lpszSystemInfo,
dwResult - 1);
Platform SDK Release: August 2001 What did you think of this topic?
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добавить переменную окружения:
set kaka=kaka
аналог:
SetEnvironmentVariable
дема тута:
http://www.pjsoft.contactbox.co.uk/resources/howto/demos/envvardemo.zip

тьфу - пыйдж переехал сюда:
http://www.delphidabbler.com/cgi-bin/software.php?callid=3&page=lib/envvars/envvars