Author Topic: DO NOT UNINSTALL THIS IF IT IS ON YOUR COMPUTER  (Read 15894 times)

Offline LaserWraith

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Re: DO NOT UNINSTALL THIS IF IT IS ON YOUR COMPUTER
« Reply #15 on: May 01, 2010, 03:12:35 PM »
I thought that people were saying their drive is now useless, and it is best to chuck it out the window into their neighbor's backyard, or something.  But I'm 99% sure it could be workable if you re-create the MBR and reformat, right?  :)

And everyone (right?) backs up their data externally, so the only problem is the reformat process, which I find is good to do anyway.

Just stay away from CTM, maybe.

Offline Endymion

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Re: DO NOT UNINSTALL THIS IF IT IS ON YOUR COMPUTER
« Reply #16 on: May 01, 2010, 03:35:51 PM »
About the sticky thread, it's rather useless. It doesn't tell nowhere what to do with test disk. You forget that not everybody is a computer wizard.
I have no clue if that member was a "computer wizard" but he sure he tried to help by sharing those info.

Guess I have not to remind you can improve over such topic with more detailed explanation about testdisk even to the point it would be possible for each member with similar issue to actually confirm the cases where corruption extend outside the MBR and partition table (by simply delaying related repair step you mentioned)

I hope you will not forget you can actually lend your help in that regard after writing such harsh comment.


As i said, restoring the MBR is not the issue, but repairing the sector chain is. All files on a drive are a chain of sectors belonging to each other. If you brake one link in that chain, then the file is broken and your data might be lost. On NTFS drives a backup table is present and can be used to repair the chain, but if the backup table is also corrupted, then the data is lost. Testdisk can repair the MBR and partition table. As far as i know can it also repair files if the chain is broken. It uses the backup table to do so. CTM performs very low level disk access and that's a risky business, cos 1 mistake in the software might cause data loss.

There was at least one member that did not use Testdisk (see quote) but MbrFix which is apparently limited to the partition table and MBR (AFAIK amounting to 512 bytes).

I didn't know about TestDisk; I ran MbrFix which set it back to when I first had CTM installed.

Whereas issue might not always be the same the solution mentioned by that member might not apply in this topic case nor the scenario you mentioned.

« Last Edit: May 01, 2010, 04:46:25 PM by Endymion »
I have learnt silence from the talkative, toleration from the intolerant, and kindness from the unkind; yet strange, I am ungrateful to these teachers.
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Offline marlonvdb

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Re: DO NOT UNINSTALL THIS IF IT IS ON YOUR COMPUTER
« Reply #17 on: May 01, 2010, 05:15:34 PM »
Guess I have not to remind you can improve over such topic with more detailed explanation about testdisk even to the point it would be possible for each member with similar issue to actually confirm if the corruption extend outside the MBR and partition table (by simply delaying related repair step you mentioned)

There are several post on this forum about members that did use MBR repair tools. There drive became "bootable" again which is at least a start in getting back the data, but the windows setup got somehow damaged. The disk was still not really usable due to several errors within windows and eventually they had to reformat and reinstall. This is why i suspect that CTM (or maybe just the installer/uninstaller) does harm the sector chains. The MBR is only used when booting up and a damaged partition table would result in lost partitions or wrong partition maps. So what is left over is file corruption. Both FAT(32) and NTFS do have a backup table. The NTFS backup table is more reliable than the FAT(32) backup table. Programs like checkdisk and also Testdisk do use those backup tables to repair damaged chains. In some posts on these forum there are messages about checkdisk messages. Checkdisk does come up at windows boot time if it detects a difference between the original and backup allocation table. If both tables are corrupted, then it's very hard to recover any data, because those programs will not have any clue on how it should be. I suspect that CTM does manipulate those tables, because it somehow stores the snapshots hidden on the drives. It need to modify the tables for that or else windows might claim a sector which is already in use by a CTM snapshot. Though feel free to correct me if i'm completely wrong.
But to jump back to the topic of repair, unfortunately can also testdisk not  repair the chains if both allocation tables are corrupted. Nor do i know of any other application that can.

About my post to ask people to post there recover actions, well i hoped to create a useful thread there with resources that could help others. So yes, i did want to help.
The problem with all the possible solutions is that they are snippered over several threads, meaning someone in need needs to look around in more than one thread to find a possible solution for his/her problem.

Some additional commend on testdisk, it's a rather good program. No doubt about that, but the last testdisk version is released in april 2009 while windows 7 got released in october 2009. I know that windows 7 uses almost the same boot process as vista did, but it is almost the same. Not 100%. The bootrec application of ms is different between vista and 7. That tool is there to repair MBR and others boot problems like BCD corruption. I just wonder why bootrec is different between vista and 7. Is there maybe a difference in the MBR? If yes, then would teskdisk still be able to work 100% correctly on win 7? It's just a thought...

Offline marlonvdb

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Re: DO NOT UNINSTALL THIS IF IT IS ON YOUR COMPUTER
« Reply #18 on: May 01, 2010, 05:24:48 PM »
I thought that people were saying their drive is now useless, and it is best to chuck it out the window into their neighbor's backyard, or something.  But I'm 99% sure it could be workable if you re-create the MBR and reformat, right?  :)

You are right there, but the reformat will erase all the pictures of there girlfriends.

And everyone (right?) backs up their data externally, so the only problem is the reformat process, which I find is good to do anyway.

My experience is that mostly only people that are experienced pc users do backup there data. More than 50% does not. Those that do not do rely on ms system restore and tools like CTM. Nothing wrong with that (if they would work), but those tools still wont help if the HDD head makes an emergency landing on the HDD surface.

Just stay away from CTM, maybe.

It would help if comodo did put it back to beta release

Offline Endymion

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Re: DO NOT UNINSTALL THIS IF IT IS ON YOUR COMPUTER
« Reply #19 on: May 01, 2010, 06:02:35 PM »
Whereas fixing MBR and partition table won't help the underlying issue might be different. 

In some cases tools like mbrfix might not apply.

I have another example when chkdsk is forced: if NTFS partition was mounted with read-write access when Windows (and CTM of course) was offline. For example, booting from WAIK 2.0/WAIK 7 LiveCD.

For example extended corruption might occur whereas a protected partition is written (or mounted with read/write settings) with an OS without CTM installed.

There are several post on this forum about members that did use MBR repair tools. There drive became "bootable" again which is at least a start in getting back the data, but the windows setup got somehow damaged.

Rebooting during uninstallation might likely result in extended corruption as well and of course there might be other reason for failure (with differet levels of data corruption).


Obviously I did not mean to generalize over the different range of often incompletely detailed scenarios but there are actual quotes I posted earlier from members who got back functinal windows installation with testdisk and mbrfix (quotes link to full posts).

On this ground I still think it might be sensible advice to repair using Testdisk and provide info about the hardware and OS setup (eg multi boot), software version and the result of fix.

I had no clue that would have been difficult to acknowledge that much whereas I find difficult to assume each new issue to be the same even more when there is not much information (or rather circumstantial one).

About my post to ask people to post there recover actions, well i hoped to create a useful thread there with resources that could help others. So yes, i did want to help.
The problem with all the possible solutions is that they are snippered over several threads, meaning someone in need needs to look around in more than one thread to find a possible solution for his/her problem.
Perhaps you might have found easier to just integrate the stikied topic you stated to be "useless" as the solution does not appear to be just speculation nor "sound like ZIP".

« Last Edit: May 01, 2010, 06:50:56 PM by Endymion »
I have learnt silence from the talkative, toleration from the intolerant, and kindness from the unkind; yet strange, I am ungrateful to these teachers.
Kahlil Gibran (1883 - 1931)

Offline LaserWraith

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Re: DO NOT UNINSTALL THIS IF IT IS ON YOUR COMPUTER
« Reply #20 on: May 01, 2010, 06:12:12 PM »
You are right there, but the reformat will erase all the pictures of there girlfriends.

My experience is that mostly only people that are experienced pc users do backup there data. More than 50% does not. Those that do not do rely on ms system restore and tools like CTM. Nothing wrong with that (if they would work), but those tools still wont help if the HDD head makes an emergency landing on the HDD surface.

It would help if comodo did put it back to beta release

Yes, I know many don't do any backup-ing.  And if they do, often it will fail if a HDD crash comes along.

I happen to backup with MozyHome (won a license), Wuala!, and Live Mesh.  I'm still trying to decide which to use.   88)

 

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