The easiest way is to put your operating system disk in the computer and do a repair.
If you have XP, then it is a nightmare and to long to explain, your better off, doing a install
of the OS, then making sure system restore is on and making a restore point.
But if you want to try and you have XP, below ill post a repair for the boot.
http://pcworld.about.com/magazine/2111p196id112479.htm
This is for recovery console.
http://support.microsoft.com/kb/314058
Vista and windows 7 are very easy to fix the MBR, you just put in the disk and it will repair it for you.
If the master boot record (MBR) becomes corrupted, the computer may not be able to boot properly. This can lead to issues such as a "missing operating system" error or a boot loop. To fix this, you may need to repair the MBR using tools like the Windows Recovery Environment or third-party software.
To fix a corrupt U2 Edition iPod, you can try restoring it using iTunes. Connect the iPod to your computer, open iTunes, select the iPod, and choose the option to restore it. This will erase all data on the iPod, so make sure to back up any important files before proceeding.
.pet files, for whatever reason, are not compatible with Petz Workshop. If you really want to edit a pet, you'll have to use a hexeditor or LNZ pro.
To correct a corrupt MBR or partition table, you can use command-line tools like "diskpart" in Windows or "fdisk" in Linux to rewrite the MBR or partition table. Another option is to use third-party disk management software that can repair or rebuild the MBR and partition table. Alternatively, restoring from a recent backup or reinstalling the operating system can also fix the issue.
Muckrakers. These people brought foreward the news of horrible stories that people were not otherwise hearing. By bringing these events to knowledge, the public went into outrage and demanded that Government fix the problem.
If the master boot record (MBR) becomes corrupted, the computer may not be able to boot properly. This can lead to issues such as a "missing operating system" error or a boot loop. To fix this, you may need to repair the MBR using tools like the Windows Recovery Environment or third-party software.
they may be corrupt, missing dll files from the specific folder and any number of other issues. Its wise to uninstall and run the boot disk selecting REPAIR to fix any key file errors then install FSpassengers on its own just in case it is conflicting with an addon
You can find here all required information http://www.howtogeek.com/howto/windows-vista/fixing-bootmgr-is-missing-error-while-trying-to-boot-windows-vista/
You need to clean your registry of missing or corrupt DLL entries. Its explained here in more detail: http://www.squidoo.com/rundllerror
it is a PSP that cannot boot up properly because it has corrupt/missing files u know ur PSP is bricked when: 1. you turn it on 2. the screen stays blank 3. after 10 seconds (or so) it shuts itself off to fix a brick, use Pandora battery or recovery flasher
If a virus persists on a PC even after formatting it is likely that the virus has been inserted into the boot sector of the hard drive - which is not rewritten when you re-format it. Assuming you are running a Microsoft OS, to fix it, boot using the install CD for the OS and run the first Repair option which will load the Recovery Console from a ramdisk (and doesn't use the hard drive for booting). This requires that your BIOS supports booting from the CD drive. Then run the 'fixboot' command. This is supposed to overwrite the boot sector. You may have to specify the drive letter of which partition to fix.
Corrupt Dragon items degrade over time. There are no npc's or player related skills to fix them, once they are fully degraded they dissapear.
you can't as far as i know
Sorry mate, unfixable
insert boot disc
You can fix your HP Touchsmart from darkening after boot up by restoring your device to the manufacturer-settings.
i have know idea