Quick answer: 

use Win32 qw(CSIDL_APPDATA);
print Win32::GetFolderPath(CSIDL_APPDATA);

[download]

This is a question the most Win32 programmers ask at some point, so it is worth posting some comprehensive info from MSDN

Whenever you access any of the special folders in the following list, your application should use the Win32 APIs to dynamically obtain the proper language-specific folder names. The preferred way to do this is using the SHGetFolderPath API with the appropriate CSIDL constant. This function behaves consistently across Windows 95, Windows 98, Windows NT 4.0, and Windows 2000.

This API is redistributable via the SHFOLDER.DLL. SHFOLDER.DLL is installed by the Windows Installer redistributable. Software vendors are encouraged to redistribute this component as much as possible to enable this support on Windows operating systems prior to Windows 2000. Windows 2000 includes this DLL as a protected system file and, as such, this DLL cannot be replaced on Windows 2000 or greater.

To help ensure your application can run on Windows 9x, Windows NT 4 as well as Windows 2000, always link to the SHGetFolderPath implementation in SHFOLDER.DLL. Windows 2000 natively implements SHGetFolderPath in SHELL32.DLL, but other versions of Windows do not include SHGetFolderPath in SHELL32.DLL.

Standard FolderCSIDL Constant Name
Alternate Startup ([user], DBCS)CSIDL_ALTSTARTUP
Alternate Startup folder (All Users profile, DBCS) CSIDL_COMMON_ALTSTARTUP
Application Data ([user] profile)CSIDL_APPDATA
Application Data (All Users Profile)CSIDL_COMMON_APPDATA
Control Panel virtual folderCSIDL_CONTROLS
Cookies folderCSIDL_COOKIES
Desktop (namespace root) CSIDL_DESKTOP
Desktop folder ([user] profile) CSIDL_DESKTOPDIRECTORY
Desktop folder (All Users profile) CSIDL_COMMON_DESKTOPDIRECTORY
Favorites folder ([user] profile) CSIDL_FAVORITES
Favorites folder (All Users profile) CSIDL_COMMON_FAVORITES
Fonts virtual folder CSIDL_FONTS
History folder CSIDL_HISTORY
Internet Cache folder CSIDL_INTERNET_CACHE
Internet virtual folder CSIDL_INTERNET
Local (non-roaming) data repository for apps CSIDL_LOCAL_APPDATA
My Computer virtual folder CSIDL_DRIVES
My Pictures folder CSIDL_MYPICTURES
Network Neighborhood directory CSIDL_NETHOOD
Network Neighborhood root CSIDL_NETWORK
Personal folder ([user] profile) CSIDL_PERSONAL
Printers virtual folder CSIDL_PRINTERS
PrintHood folder ([user] profile) CSIDL_PRINTHOOD
Program Files folder CSIDL_PROGRAM_FILES
Program Files folder for x86 apps on Alpha systems CSIDL_PROGRAM_FILESX86
Programs folder (under Start menu in [user] profile) CSIDL_PROGRAMS
Programs folder (under Start menu in All Users profile) CSIDL_COMMON_PROGRAMS
Recent folder ([user] profile) CSIDL_RECENT
Recycle Bin folder CSIDL_BITBUCKET
SendTo folder ([user] profile) CSIDL_SENDTO
Start menu ([user] profile) CSIDL_STARTMENU
Start menu (All Users profile) CSIDL_COMMON_STARTMENU
Startup folder ([user] profile) CSIDL_STARTUP
Startup folder (All Users profile) CSIDL_COMMON_STARTUP
System folder CSIDL_SYSTEM
System folder for x86 applications on Alpha systems CSIDL_SYSTEMx86
Templates folder ([user] profile) CSIDL_TEMPLATES
User’s profile folder CSIDL_PROFILE
Windows directory or SYSROOT CSIDL_WINDOWS

In reply to Re: How to get location of Desktop folder on Win32 by EdwardG
in thread How to get location of Desktop folder on Win32 by Anonymous Monk

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