The Windows boot process does not use the functionality of every device connected to the system. In some devices, only a subset of functionality is used. A number of devices are not accessed at all during the boot process. To ensure that a device is operating correctly, you must test all of its functions, which is what PC-Doctor does.
The Windows boot process will not answer any of the following questions:
PC-Doctor answers these questions and many more.
If you cannot boot to Windows, it is difficult to determine if the problem is defective hardware or a Windows configuration problem. Diagnostics such as PC-Doctor for DOS or PC-Doctor for Linux can run from boot floppies or boot CDs outside of the system's primary operating system. These diagnostics can test the hardware without using the computer's primary operating system.