Hello Mr.Ahmed

before installing pls check the OS requirements for wincc flexible & it need any one of below OS
Windows XP Professional SP2 / SP3, Windows Vista (Business, Ultimate) 32 Bit-Editions.

Also if it is working in Windows Vista pls check the MSDE is properly istalled and the mssql service is started / running.

regards
S.Karthik

Hello

Look at Which Microsoft operating system (Windows XP/2000/Vista) can be used with which SIMATIC WinCC flexible? In your case WinCC Flex 2007 is uncompatibility wih OS, means you would have success to install without problems, but after you can receive some errors.

regards