FIX-CIH.EXE   Complete Recovery of CIH-Destroyed Drives

PLEASE NOTE: The FIX-CIH freeware has created some confusion with regard to our commercial SpinRite 5.0 product: FIX-CIH presumes that the target drive is healthy and functioning well. It performs no analysis or recovery of "marginal" or "unreadable" data (the way SpinRite does), it only recontructs the data that was lost due to a CIH (Chernobyl) virus attack.    Our commercial SpinRite 5.0 product is the best utility ever created for assuring the integrity and reliability of personal computer mass storage. For assuring the safety of your data, nothing beats SpinRite. Once FIX-CIH has brought your drive's partitions back online, SpinRite 5.0 can be used to assure and maintain the integrity of the drive's data storage over the lifetime of the drive.

During the Development . . .

In order to provide the quickest availability of FIX-CIH to everyone during the final stages of FIX-CIH's development I released a SERIES OF VERSIONS each with greater capability than the previous. This page details FIX-CIH's release history.

The Premiere Release:
This version did NOT seek out and recover partitions beyond the first one. It ONLY recovered the drive's first FAT32 partition.

Release #2:   (5/20 @ 15:00 PST)

Research and Troubleshooting Additions Only:
The release of FIX-CIH that's now on our FTP server (http://grc/com/files/fix-cih.exe) now sports a nice division overflow handler to let us track down the PHOENIX BIOS problems, and also recognizes when it was already used to recover a drive so that it will be willing to be re-run if we need to change its recovery strategy or collect more data.

PLEASE NOTE: This release does NOT act any differently than yesterday's. If it didn't work yesterday, it still won't work today. I don't mean to get your hopes up with this release that is only intended to let us gain a deeper insight into what's going on when FIX-CIH refuses to work.

Release #3:   (5/21 @ 12:15 PST)

Fixed Y2K Directory Entry Misfire
I've received a number of reports from people whose system's had some year 2000 (or later) directory entries. My directory entry filter was presuming that such entries were invalid. It is smarter now and tolerant of unlikely dates. Therefore FIX-CIH will now agree to work on those systems where it was refusing to for that reason.
Added Code to Report BIOS-Related Division Overflow.
The division overflow handler in release #2 did provide some useful feedback, so this release adds a new screen to catch the error before it happens.

FOR USERS WITH MORE THAN ONE PARTITION It is TOTALLY OKAY for you to use this release of FIX-CIH to recover your First Partition Only! I've forgotten to mention that FIX-CIH has been leaving a small "recovery fingerprint" on any drive it fixes so that future multi-partition releases WILL proceed to recover your other partitions! I have edited the warning screen for Release #4 to make this clear, but in the mean time you can use Release #3 and COMPLETELY IGNORE the warning about not proceeding if you have multiple partitions.

Release #4:   (5/22 @ 12:30 PST)

 Unconfirmed Cure for Phoenix/AMI Bios Problems
For some bizarre reason, some Phoenix and AMI BIOSES, when asked for the physical size of the drive, return a count of ZERO sectors per track. This was causing FIX-CIH's division overflow errors. I've added code to catch and work around this condition.
 Changed Message to Permit Use with Multiple Partitions
Even though FIX-CIH does not yet recover multiple partitions (I hope to work on that today) it's fine to use it now for the recovery of the drive's first FAT32 partition. Running it again later (after it has multi-partition recovery capability) will recover the rest.
 Added Windows DOS Box Prohibition
I was shocked to learn that people were running FIX-CIH from within Windows. That scares me to death since lord only knows what mischief Windows might be up to. So the program now senses when it's being run within a multitasking environment and refuses to proceed. Better safe than very sorry!
 Added Release Number Tracking to First Screen
To help users know which release of FIX-CIH they have, release 4 and later identify themselves at the top center of the first displayed screen.

Release #4.1:   (5/23 @ 11:20 PST)

 Incremental Improvement in Y2K Filter Heuristic
I'm working on FIX-CIH's comprehensive multi-partition reconstructor, which will be the big news in Release #5, and which will complete my work on FIX-CIH with the exception of addressing any remaining bugs. But in the mean time I have made a small improvement to FIX-CIH's Y2K directory filtering heuristic which should allow it to run on those few remaining systems where it was mis-firing.

A NOTE For People Waiting For Release 5 It's getting close to being ready for you.   (5/26 @ 14:45 PST) I want to thank you for your patience, and to let you know that, finally, all I'm doing is working on the multi-partition recovery release (#5) of FIX-CIH.    Over the past few days of working with people who still had trouble after release #4.1, ALL other bugs and strange behaviors seem to have been eliminated. So I'm finally able to focus only on adding the multi-partition capabilities to FIX-CIH. I just wanted you to know that I'm cranking away on it.

Sheesh!   (5/27 @ 22:13 PST)

 Dealing with Microsoft's Bugs Today . . .
I'm nearly done.
   But earlier today I stumbled over an incredible bug in Microsoft's FDISK program that messes up a bunch of my assumptions. Not that you care (it's my problem, I know) but it turns out that FDISK's extended partition tables have valid-looking but invalid in fact, cylinder boundary entries. Unbelievable but true. Thus, my heuristic algorithms, which carefully scan the unallocated regions of the drive, examining every sector and looking for possible lost extended partition tables, were not finding them! I couldn't figure it out until I watched my code discard a totally valid extended partition table . . . and I saw why!
   Anyway, I'll rewrite my heuristic partition table finder and then I'll have Release 5 ready for you!

   NOTE: This screw-up will mean that FIX-CIH will need to re-process and perhaps re-size those first partitions that it already reconstructed since it may have MISSED SEEING an extended partition table which it was looking for as a clue when setting the absolute partition size.

Release #5:   (5/28 @ 16:00 PST)      At long last It's DONE!

 Complete Multi-Partition Discovery and Reconstruction!
With this fifth major release of FIX-CIH, the program is not only functionally complete, but has already been quite well tested by many thousands of people who have successfully used it to recover their drives which were destroyed by the very malicious CIH (Chernobyl) virus.
   As always, I will be quite interested in learning of any CIH-destroyed, FAT32 drives, which this freeware FIX-CIH program is unable to reconstruct.

Release #6:   (5/29 @ 12:00 PST)

 Recovery of Non-Primary Partitions EVEN IF the first was FAT16!
A number of people lost drives with multiple FAT16 parititons. With this release of FIX-CIH, and by using the special command line option /SkipFirst, FIX-CIH will reconstruct a drive's main partition table (Master Boot Record or MBR) EVEN IF the first partition can not be recovered for any reason.

If FIX-CIH won't recover your first partition, because it was formatted with a 16-bit FAT, you can start FIX-CIH with this command line to recover the REST of your drive's partitions:

Release #6.1:   (5/31 @ 12:15 PST)

 Optional Alternative Root Directory Finding Strategy
A few people have reported that after FIX-CIH reported an apparently successful reconstruction of their drive, there "wasn't anything there" after rebooting their system. This is caused when FIX-CIH's heuristic root directory finder locates the wrong cluster as the root directory. It's easily repaired when the proper cluster is known. So, I've added a command-line option /BootRoot to cause FIX-CIH to utilize an alternative root directory finding strategy which can (only) be used when the lost partition had been bootable.

If FIX-CIH believed that it successfully recovered your first partition, but nothing was there after the reboot, AND IF that partition had been the system's primary bootable partition, you can try re-running FIX-CIH with this command line option:

Best of luck with FIX-CIH! If this release doesn't work for you I'll keep working on it until it does! PLEASE let me know!

Would You Share Your Success? When FIX-CIH works for you, I would LOVE to hear about it! (And, of course, I want to hear from you if it doesn't so I can make it work for you!) So, if you would take a moment to share your FIX-CIH SUCCESS STORIES with me, I will create a web page here to share them with everyone! (Your name and eMail address will be removed for confidentiality.)