I got called out to a wreckers yard, to fix an infected Windows XP Computer.

It was a bit tricky, and once the infection was removed, the computer was left unable to start most exe files (some file associations were corrupt).

By that stage, it was closing time, so it was better for me to take the computer back to the office, and fix the problem during spare moments in my evening.

Once that was complete, I let the HDD defragment overnight.

The next morning, I closed the defrag window, and restarted the PC.

And then I got a bios message that said: operating system not found.

Great 🙁

Anyway, a bit of extra work, but it should be something trivial, like doing a chkdsk

I plugged the drive into the office computer, and windows says:

Disk/Drive is not formatted. Do you want to format it?

Obviously not.

I try UBCD4Win, but it also cannot recognise the partition as NTFS.

And a chkdsk will not work at all.

Using UBCD4Win, I run fixMBR, but that doesn’t help.

So I try Easeus Partition Manager, but after scanning for a few hours, it cannot detect and fix the problem.

I then try a few different partition tools, and I get some very strange results.

Some will immediately detect the partition as NTFS, and show that there is nothing wrong with the files and folders on the partition.

Others will just scan for a few hours, and not find anything.

How can similar software give such different results.

And most forums on the net are full of suggestions like “use data recovery software, then reformat”… It really shouldn’t be necessary.

I’m sure there must be a simple fix to get the filesystem restored.

So, after spending most of the day on this, with the customer getting very impatient about getting their computer back, I find all sorts of interesting pieces of information:

• The NTFS filesystem is identified using the number “07”… in this case, some partition tools say its 07, other say its 00
• The filesystem type is stored in 2 places: MBR and boot sector

So, its starting to look like the MBR and the boot sector have conflicting information about the filesystem type.

So how to fix it?

• Boot from a windows XP CD
• select recovery console
• at the command prompt, enter: fixboot c:

For some reason, I kept thinking “this is a filesystem problem, not a boot problem… so fixboot will not help”.

So its a happy ending after a very frustrating day!

And I am very annoyed at these “partition recovery” companies!

Before starting a partition recovery process that could take many hours, how difficult is it to check that the filesystem type is consistent (rather than just looking at either the MBR or the boot sector)?