It is not at all important to do a defrag if you just installed an operating system. It is usefull when you have removed software or just before installing new software.
false
yes all hard drives must be reformatted before installing an operating system.
Yes. All Windows based file systems require periodic defragmentation for optimal performance. FAT, FAT32 and NTFS file systems all require defragmentation.
Windows games are written to work with the Windows operating system. The Mac does not use the Windows operating system and so the game will not be able to work on a Mac. You will need to install the Windows operating system on your Mac or some software that emulates the parts of the Windows system that the game needs to have a Windows game work on a Mac.
Hard drive defragmentation is not difficult, and there is software available for this task for any operating system. Windows includes as part of the operating system "Disk Defragmenter" (in Accessories/System Tools); there are also free third-party tools available like Auslogics Disk Defrag, MyDefrag, and Defraggler. The Macintosh operating system has basic defragmentation routines which run automatically, but should you wish you can purchase Disc Warrier or iDefrag.
The OEM license.
Just make sure you are installing a version that is designed for your Operating System (OS). i.e. Windows 7, Windows Millennium, Windows 2000, etc.
NTFS
All hard drives must have at least one partition to be usable by an operating system, even if the partition uses the entire drive. If you are installing an operating dissimilar from the one you are using currently (ie. Windows XP and FreeBSD), you should partition the disk from that system's installer, not in Windows.
The OEM license.
Installing any pirated software leaves you at risk of prosecution and the seizure of your computers (depending on your location). Installing any version of Windows (legitimate or otherwise) on a Mac means that it is liable to be infected with the thousands of viruses that exploit the Windows operating system. A pirated version of Windows may well include code that will be exploiting and compromising your computer.
All windows are made with a thermal break inside the frame.