In order to run Windows Vista you must have at least an 800 MHz processor (1 GHz is recommended), 512 MB RAM (1 GB is recommended), 15 GB of hard disk space (20 GB is recommended), and a DirectX 9 graphics card.  Different programs will have different system requirements. To check your system specs in Windows XP, open the Start menu and right-click My Computer. From the menu, select Properties. This will open the System Properties window. In the General tab, your system specifications will be listed under the Computer heading. If you are upgrading from another OS, you will lose all of your files and programs. The programs can’t be backed up; they will need to be reinstalled. Any files—including documents, music, pictures, and videos—that you want to save need to be copied to a backup location. You can use DVDs, CDs, external hard drives, flash drives, or the cloud, depending on how much data you have to backup. To do this, restart the computer and enter the setup screen when the manufacturer logo appears. The key to do this will be displayed, and varies by manufacturer. The most common keys are F2, F10, F12, and Del.  Once in the BIOS menu, select the Boot menu. Change the order of devices so that your computer boots from CD before booting from the hard drive. Save your changes and exit. Your computer will restart. If you are installing from a flash drive, then you will need to set the BIOS to boot from removable storage.
تفقّد مواصفات الجهاز. احتفظ بنسخة احتياطية من بياناتك. غيّر إعدادات BIOS للإقلاع من القرص الضوئي.