Смотрим, что установленно в системе

Пример позволяющий просмотреть установленные в системе программы.

#include <iostream.h>
#include <conio.h>
#include <windows.h>

int main()
{
 LONG lResCode;
 DWORD dwValue = 256,dwIndex = 0;
 char szName[256];
 HKEY hKey,hKeys;
 char szPathReg[MAX_PATH] = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall";
 LONG lRes=RegOpenKeyEx(HKEY_LOCAL_MACHINE,"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall",NULL,KEY_ALL_ACCESS,&hKey);
 if(lRes!=ERROR_SUCCESS){cout<<"Error RegOpenKeyEx"<<endl;}
 else
 {
 do
 {
 dwValue = 256;szName[0]='\0';
 lResCode = RegEnumKey(hKey,dwIndex,szName,dwValue);
 if(lResCode == ERROR_SUCCESS)
 {
 cout<<"--------------------------------------------------\n"<<szName<<" = ";
 lstrcat(szPathReg,"\\");
 lstrcat(szPathReg,szName);
 if(RegOpenKey(HKEY_LOCAL_MACHINE,szPathReg,&hKeys)==ERROR_SUCCESS)
 {
 if(RegQueryValueEx(hKeys,TEXT("DisplayName"),NULL,NULL,(LPBYTE)szPathReg,&dwValue)==ERROR_SUCCESS)
 {
 CharToOem(szPathReg,szPathReg);
 cout<<szPathReg<<endl;
 }
 else{cout<<"No DisplayName"<<endl;}
 }
 RegCloseKey(hKeys);
 szPathReg[0]='\0';
 lstrcpy(szPathReg,"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall"); 
 }else{cout<<"..."<<endl;}
 dwIndex++;
 }while(lResCode != ERROR_NO_MORE_ITEMS);
 }
 RegCloseKey(hKey);
 RegCloseKey(hKeys);
 cout<<"Press any key to continue"<<endl;
 while (!getch());
 return 0;
}