When Windows fails to boot it is normally caused by you installing a program or device and it has caused a conflict with one or more other programs. This will no doubt give you plenty of heartache if you're not certain which program caused Windows to not boot up.
If you recently installed a program or application and know where it was installed,you may be in much better shape as for as correcting error. Here are common ways to correct problem of your computer not completely booting up or not booting up at all.
If your computer will not boot-up at all,hopefully you have made a good emergency boot disk. You can always make a windows startup disk by creating one from another computer running Windows 98 or Me.Perform following if your computer won't Boot-Up At All.
FIRST......Put your boot floppy disk in floppy drive and turn on PC.On some computers, you may have to access bios and select Boot priority to your A: drive.Save any changes and select "Start Computer without CDROM support" and press Enter.Once you are at A prompt,type dir c: and press enter.
If your programs and other files are present,try restoring your system Registry by following steps below.This may repair Windows,the Config. Sys and autoexec.bat files to where PC may boot up normally.When files are present,its a good indication of a good hard drive.
SECOND......To correct problem of your computer not booting up,type in "fdisk /mbr" and press Enter to restore your master boot record.Type "Scandisk C:" to check hard drive for errors that have occurred. You can also type "Sys C:" to hopefully restore files needed to boot up your computer.
THIRD......If above procedures fail to repair your computer,you can repeat first part of step one above and select "Start Computer With CDROM Support" re-install Windows.
Making A Windows XP Bootable Floppy Windows XP users should create a boot disk now by placing a formatted blank diskette in A: drive, open Windows Explorer to C:,select Tools,Folder Options ,show Hidden files and and folders,then View Tab. Now you uncheck "Hide Protected Operating System Files (recommended).You will see a warning and click Yes and click OK.Copy files ntldr,ntdetect.com and boot.ini onto disk.Remove disk and label it Windows XP Boot Disk.