Frequently Asked Questions

Chances are, others have the same questions that you do. Therefore, we have taken the common questions for Diskeeper, Sitekeeper and Undelete and provided the answers (and the questions) below in our Frequently Asked Questions section. Simply select the product below that you have questions about. If you can’t find the answer you’re looking for, you can submit a tech support question here.

Diskeeper | Sitekeeper | Undelete

Question
Black screen when restarting the computer system on a boot partition that is NTFS.
Answer
You likely have a situation where your Boot/System partition is too large for the BIOS to read from end to end. Please see the following data and suggested solution. During bootup, NT uses the BIOS primitive INT 13 for disk I/O. The INT 13 interface cannot access cylinders past 1024. The maximum amount of sectors accessible to the INT 13 interface is therefore Cylinders * heads * sectors = 1024 * 256 * 63 = 16,515,072 Hence, the total amount of space accessible to the INT 13 interface is: sectors * 512 bytes = 16,515,072 * 512 = 8,455,716,864 bytes or 7.875 GB The above calculation was done for a device with 1024 Cylinders, 256 Heads, 63 Sectors Per Track Not all drives can be configured that way due to size, however. If, for example, the drive is configured so it has, for example, 2048 Cylinders, 128 Heads, 63 Sectors Per Track The 1024 Cylinder limit still applies, so we do the arithmetic: 1024 * 128 * 63 * 512 = 4,227,858,432 bytes, Which is HALF the space of the previous drive. All we did is half the number of heads and double the number of cylinders. But since the 1024 cylinder limit still applies, the amount of space usable by NT for boot files is HALF that of a "correctly configured" drive. As a result, while the first drive can be used in its entirety for booting NT, only HALF the second drive can be used for booting NT EVEN THOUGH THE DRIVES HAVE THE SAME TOTAL CAPACITY. We have previously received the following data: Type = 3166 Mb cylinders = 6136 heads = 16 sectors = 63 When we do the math, 10241663*512= 504 MB, so no part of a bootable NTFS partition on that drive can safely live past the 504 MB boundary, or roughly 1/6th of the physical drive. This is substituting the 1024 cylinder maximum for the 6136 cylinder figure provided. The basic problem is that the INT 13 interface cannot access a cylinder past 1024. If you are able to configure the drive so that it uses, for example 1024 cylinders, 96 heads and 63 sectors, then you would be able to use the whole drive for booting NT. You would need to find out from the disk vendor what the possible geometries are for the drive; the above figures are just a guess. The Microsoft Knowledge Base article http://support.microsoft.com/support/kb/ARTICLES/Q122/9/26.asp discusses the situation in detail. Here are the steps to handle the problem. If you already have a boot floppy that contains a correct version of the files listed in step 2, you can use that to boot your system. If not, here is how to create one: 1. Format the floppy in another Windows NT system, (you must format it in Windows NT so that the boot sector on the disk can find and run NTLDR) 2. Copy these three files from the root of the C: partition to the floppy : boot.ini, ntldr and NtDetect (you must be certain the Windows NT is installed to the same directory on the target system as it is on the system that you are copying the files from). You can then boot from this floppy. If this does not work, you need to alter your CMOS so that it looks to the floppy before looking to the hard drive for boot files. If you are not certain on how to do this please contact me either by phone (800) 829-4357 or by return e-mail. I can assist you with this setting. You can then delete the ntldr from the root of the C: partition and then copying the ntldr from the boot floppy to the root of the C: partition. This may copy the NTLDR file into an address that is close enough to the beginning of the partition for the FAT boot code to find. If this works, exclude the ntldr from Diskeeper's online operations and do not run BOOT TIME CONSOLIDATION. This will keep DISKEEPER from ever being the source of this problem, but, as mentioned above, this problem can occur anyway. Keep your boot floppy in your tool box should you see this again. If copying the file back does not solve the problem, please contact me for further recommendations. To get the CMOS settings for your drives: 1. Place the attached copy of DriveInfo.exe in your WinNT/System32 directory. 2. Run Driveinfo.exe and capture the output: DriveInfo > c:\DriveInfo.txt 3. Click the link below indicating that this solution did not solve the problem and then Forward file created back to our technical support team as an e-mail attachment.

Question

Black screen when restarting the computer system on a boot partition that is NTFS.

Answer

You likely have a situation where your Boot/System partition is too large for the BIOS to read from end to end. Please see the following data and suggested solution.

During bootup, NT uses the BIOS primitive INT 13 for disk I/O. The INT 13 interface cannot access cylinders past 1024. The maximum amount of sectors accessible to the INT 13 interface is therefore

Cylinders * heads * sectors = 1024 * 256 * 63 = 16,515,072

Hence, the total amount of space accessible to the INT 13 interface is:

sectors * 512 bytes = 16,515,072 * 512 = 8,455,716,864 bytes

7.875 GB

The above calculation was done for a device with

1024 Cylinders, 256 Heads, 63 Sectors Per Track

Not all drives can be configured that way due to size, however. If, for example, the drive is configured so it has, for example,

2048 Cylinders, 128 Heads, 63 Sectors Per Track

The 1024 Cylinder limit still applies, so we do the arithmetic:

1024 * 128 * 63 * 512 = 4,227,858,432 bytes,

Which is HALF the space of the previous drive. All we did is half the number of heads and double the number of cylinders. But since the 1024 cylinder limit still applies, the amount of space usable by NT for boot files is HALF that of a "correctly configured" drive.

As a result, while the first drive can be used in its entirety for booting NT, only HALF the second drive can be used for booting NT EVEN THOUGH THE DRIVES HAVE THE SAME TOTAL CAPACITY.

We have previously received the following data:

Type = 3166 Mb
cylinders = 6136
heads = 16
sectors = 63

When we do the math, 1024*16*63*512= 504 MB, so no part of a bootable NTFS partition on that drive can safely live past the 504 MB boundary, or roughly 1/6th of the physical drive. This is substituting the 1024 cylinder maximum for the 6136 cylinder figure provided.

The basic problem is that the INT 13 interface cannot access a cylinder past 1024. If you are able to configure the drive so that it uses, for example 1024 cylinders, 96 heads and 63 sectors, then you would be able to use the whole drive for booting NT. You would need to find out from the disk vendor what the possible geometries are for the drive; the above figures are just a guess.

The Microsoft Knowledge Base article

http://support.microsoft.com/support/kb/ARTICLES/Q122/9/26.asp

discusses the situation in detail.

Here are the steps to handle the problem.

If you already have a boot floppy that contains a correct version of the files listed in step 2, you can use that to boot your system. If not, here is how to create one:

1. Format the floppy in another Windows NT system, (you must format it in Windows NT so that the boot sector on the disk can find and run NTLDR)

2. Copy these three files from the root of the C: partition to the floppy : boot.ini, ntldr and NtDetect (you must be certain the Windows NT is installed to the same directory on the target system as it is on the system that you are copying the files from).

You can then boot from this floppy. If this does not work, you need to alter your CMOS so that it looks to the floppy before looking to the hard drive for boot files. If you are not certain on how to do this please contact me either by phone (800) 829-4357 or by return e-mail. I can assist you with this setting.

You can then delete the ntldr from the root of the C: partition and then copying the ntldr from the boot floppy to the root of the C: partition. This may copy the NTLDR file into an address that is close enough to the beginning of the partition for the FAT boot code to find. If this works, exclude the ntldr from Diskeeper's online operations and do not run BOOT TIME CONSOLIDATION. This will keep DISKEEPER from ever being the source of this problem, but, as mentioned above, this problem can occur anyway. Keep your boot floppy in your tool box should you see this again.

If copying the file back does not solve the problem, please contact me for further recommendations.

To get the CMOS settings for your drives:

1. Place the attached copy of DriveInfo.exe in your WinNT/System32 directory.
2. Run Driveinfo.exe and capture the output:

DriveInfo > c:\DriveInfo.txt

3. Click the link below indicating that this solution did not solve the problem and then Forward file created back to our technical support team as an e-mail attachment.

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