Member Avatar for sDJh

Hello all together,

my old computer with WinME got a really bad virus that I couldn't remove so I reinstalled the OS. The trouble is, that after the setup BIOS tells me that no OS is installed - which seems to me that the MBR (first sector with information about OSs and partitions) is not updated by Win. What can be the problem?

Many thanks in advance
Simon

PS Personally I just can think of one other possibility. I can delete the first partition completely with Linux so that Win creates a ew one. Do you think that might help?

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  • Latest Post Latest Post by firekid1239

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Generated

Quick, practical checklist for based on the symptoms and the replies from and .

First checks (non‑destructive)

  • Confirm the BIOS actually sees the hard disk and that the HDD is first in the boot order. If there are multiple drives, the installer may have written boot code to a different disk.
  • Look in the BIOS for any MBR/boot protection setting (as suggested) and disable it if present.
  • Do not delete partitions yet — back up any personal data first.

How to verify and repair the boot records

  • Boot from a Windows 98/ME startup floppy or any DOS-capable rescue CD, or from a Linux live CD.
  • Inspect the partition table. In DOS use fdisk to list partitions and check which partition is marked Active. In Linux use fdisk -l or parted -l.
  • If no primary partition is active, set the Windows partition active with fdisk. Then rewrite a standard Windows 9x MBR with fdisk /mbr. If the partition boot sector is corrupt you can restore system files with sys c: from a Win98/ME startup disk.
  • If you prefer Linux tools, use them only if comfortable; utilities like ms-sys can write a Windows MBR but are advanced and risky. Avoid raw dd unless you know exactly what you are doing.

About deleting the partition

  • Deleting the first partition and letting Windows recreate it will usually force the installer to write a fresh partition table and MBR, so yes, it can help — but it destroys data. Try the repair steps above first. If repairs fail, back up everything from Linux, recreate the partition table, then reinstall.

If problems persist, consider hardware causes (failing disk, wrong controller mode, jumper settings) or a failed/incomplete install. For a deeper reference on the MBR concept see the Master boot record overview: Master boot record.

Recommended Answers

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Member Avatar for jbennet

In the BIOS check sure that theres not an option called aomething like Bootloader/MBR antivirus/write protect

Some BIOSes have it as an option to write protect the MBR to protect it viruses hiding in there. However, this is bad if you are installing an OS, obviosly...

Member Avatar for firekid1239

Your best bet is something called Hirens Boot CD. You can download it for free and what it offers is about 300 hundred different tools to do pretty much anything you could imagine both software and hardware wise. I forgot the site that hiren has set up to download it but there is a Wiki that you should read about it before you download. It is truly the most versatile cd I have ever used. Just search Google.

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