Uninstall "lilo" or "grub"

From a boot disk for Windows 98

Insert your boot disk and restart your computer to boot same.

Go to prompt A: \" and type:
fdisk / mbr

Restart your PC.

From the installation CD of Windows 2000 or Windows XP

Insert your installation CD and restart your pc to boot same.

Once the installation menu from your Windows appears on your screen, select "Repair Windows Installation" by pressing R.

Then use the repair manual for the console by pressing C.
Once the console to the screen, choose the Windows system where you want to work (default 1), then type your administrator password (if you do not type anything and confirm with "enter") and finally type:

fixmbr

Type "Exit" to exit.

Restart your PC.

Since the CD install Mandriva

Insert your installation CD and restart your PC to boot it.
Then press "F1" or "ESC" (escape key) to switch to text mode, or with new versions, select the mode "backup system".

Once the "prompt" (or "prompt") "Boot:", type:
linux rescue
Once the screen loaded, Choose: (help the arrow keys "up" and "low" to highlight your choice)

Restore Windows Boot Loader

Confirm by pressing "Enter" then move to "OK" using the "TAB" or the right arrow key.

A new screen will appear warning you that the system has found a "Linux Bootloader" on your hard drive and it will now replace it with a "Windows Bootloader”.

Continue by pressing "Enter" to confirm or if you want to step back by pressing "n".

Using SuperGrubDisk

If none of the above works, you can use this software SuperGrubDisk