The data you're after is in the registry in
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
Every entry there has a member string called DisplayName with the name of the program.
To access the registry from within your program, you'll want to use these functions:
RegOpenKeyEx[
^] to open HKEY_LOCAL_MACHINE
RegQueryInfoKey[
^] to open \SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
RegEnumKeyEx[
^] to loop through all the installed programs
RegEnumValue[
^] to loop through all the available data on this program
RegQueryValueEx[
^] if you know in advance which value you want to read (e.g. DisplayName).
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