FAQ (frequently-asked questions)

For "Disk Shredder 4" users, "FAQ for Users" are also available.

FAQ on the necessity of Disk Shredder 4 (Table of Contents)
Q.1 Why is it not possible to delete the data completely by putting a file in Recycle Bin and deleting a file from Recycle Bin in Windows? Q.2 Is it possible to erase the data completely by formatting a hard disk? Q.3 Is it possible to erase the data completely by reinstalling OS and software from the recovery CD-ROM? Q.4 If PCs are rental or leased, is it enough to use a data-erasure service by rental/leasing companies for protecting data leak? Q.5 In what situation should I use "Disk Shredder 4"? Q.6 Why does Disk Shredder 4 write random numbers? Is it insufficient to write 0(zero)? Q.7 How should I re-use a hard disk erased by "Disk Shredder 4"? Q.8 I hear that "Disk Shredder 4" erases the hard disks' data completely. What is the specific meaning of "erasing data completely"? If a hard disk has a hardware defect which is not writable by a software, how does "Disk Shredder 4" react?
FAQ on the operations of Disk Shredder 4 (Table of Contents)
Q.1 How can I start up "Disk Shredder 4"? Do I have to install the software to a hard disk? Q.2 There is a lot of PCs I have to erase. Give me some suggestions for usage? Q.3 We want to additionally purchase multiple packages of "Disk Shredder 4" for concurrent usage and backup. Can you give me a discount?
FAQ on the software license agreement of Disk Shredder 4 (Table of Contents)
Q.1 I understand that I run "Disk Shredder4"(FD version) by using a single FD alone. But if I use the same FD many times, won't the FD be damaged sometime in the future? Q.2 Can we make backup copy of FD or CD-ROM before running "Disk Shredder4"? Q.3 Is there any maintenance contract for "Disk Shredder 4"? Q.4 While we are waiting for a replacement for a damaged FD or CD-ROM, can't we use "Disk Shredder4"? Q.5 What if we have a bad sector that can not be written into using ordinary software? Q.6 Q.6 I work at a PC rental agency. Is it all right for us to let the customers handle the data erasure themselves? That is, is it all right for us to send "Disk Shredder 4" FD or CD-ROM as well as the PC hardware, and when the rental period expires, we ask the customers to run "Disk Shredder 4" if they want to clean the disk?

FAQ on the necessity of Disk Shredder 4

Q.1 Why is it not possible to delete the data completely by putting a file in Recycle Bin and deleting a file from Recycle Bin in Windows?
A hard disk mainly consists of "management area" and "data area". If you liken a hard disk to a warehouse, you can compare "management area" to a list of commodities, "data area" to a storage area. Only file information(a file name, etc.) is stored in "management area", and the real file data is stored in "data area". The operation of deleting a file from Recycle Bin means deleting only a file information(corresponding to a list in a warehouse) from "management area". So, a file data itself(corresponding to the goods in a warehouse) is still stored in "data area". That's why lots of files can be restored by a commercial file-restoring software by restoring file managing information from "data area".

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Q.2 Is it possible to erase the data completely by formatting a hard disk?
No. Contents of information erased by formatting depend on OS or commands. However, if you are using Windows XP, for example, erased area by "Standard Format" or "Quick Format" is "management area"(refer to Q.1) only. So, files can be restored by a commercial file-restoring software, because the contents of "data area" still remain.

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Q.3 Is it possible to erase the data completely by reinstalling OS and software from the recovery CD-ROM?
No. If you reinstall OS and software on a whole hard disk using the recovery CD-ROM, the recovery CD-ROM just overwrites a part of "data area". In many cases, the data you saved still remain.

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Q.4 If PCs are rental or leased, is it enough to use a data-erasure service by rental/leasing companies for protecting data leak?
No. As you can find the laws protecting personal information such as Data Protection Act, Privacy Act and Private Information Protection Law around the world, companies have to manage personal information and protect data leak by law.
Surely, using a data-erasure service by rental/leasing companies is a part of enhancement of information management. But, the laws require companies themselves to have a complete privacy policy. In other words, companies themselves have to have their own defense measures. You should not leave the protection of personal information to others. This is the first step.
It is recommended to erase data completely by yourself first, when you recycle/discard PCs or when you return PCs to rental/leasing companies.

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Q.5 In what situation should I use "Disk Shredder 4"?
The situation that PCs with classified information are recycled/discarded or diverted to other use.
It is important to erase the unwanted classified information completely for protecting data leak in the future. The data-erasure is needed when you recycle/discard PCs, and even when you divert PCs to other use.
The situation that PCs are returned to rental/leasing companies due to expiration.
You can easily erase the data completely by "Disk Shredder 4". You may prefer to forget about the data erasure, when you return PCs which are leased for a short period at exhibitions.
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Q.6 Why does Disk Shredder 4 write random numbers? Is it insufficient to write 0(zero)?
If the patterned data such as only 0 or only 1 is written to a hard disk, the contents of previous data could be guessed by reading residual magnetism in a hard disk with a special equipment. So, Disk Shredder 4 writes random numbers to be destroy a specified written pattern in a hard disk. Besides, Disk Shredder 4 overwrites random numbers more than once to prevent a special equipment from reading the original data. In this way, Disk Shredder 4 has advanced functions which erases data of PCs with classified information securely.

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Q.7 How should I re-use a hard disk erased by "Disk Shredder 4"?
You can re-use a hard disk by making disk partitions, formatting a disk, and installing OS newly. As the general procedure for Windows, start up PC with a setup disk or a recovery disk. For detailed information, refer to your PC manual.

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Q8 I hear that "Disk Shredder 4" erases the hard disks' data completely. What is the specific meaning of "erasing data completely"? If a hard disk has a hardware defect which is not writable by a software, how does "Disk Shredder 4" react?
"Disk Shredder 4" erases the data completely by writing unmeaning data on the entire area of a hard disk, with the standard command for a hard disk(ATA command). When a writing error occurs due to a hard disk's hardware defect(bad sectors, etc), Disk Shredder4 skips such bad sectors and continues processing. At the end of the processing, Disk Shredder4 reports the number of such skipped sectors. Please be warned that the data in such bad sectors may not have been overwritten. To erase the data on bad sectors, you need a physical or chemical method. You can find reference information at Instruction Manual supplied with the product.

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FAQ on the operations of Disk Shredder 4

Q.1 How can I start up "Disk Shredder 4"? Do I have to install the software to a hard disk?
"Disk Shredder 4" boots from FD or CD-ROM. You don't have to install the software to a hard disk. But, the media(FD or CD-ROM) has to be inserted in the drive of the target PC, until the data-erasure is over.

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Q.2 There is a lot of PCs I have to erase. Give me some suggestions for usage?
Although "Dish Shredder 4" can be used repeatedly with no limit, only one PC can be processed by a single Disk Shredder4(a single CD or FD) at the same time. If you need to work on many PCs at once, you are required to buy the necessary number of "Disk Shredder 4" products. For your information, the erasure time changes significantly, depending on the erasure method, the PC's hardware specification and the hard disk's capacity. It may take hours and hours to erase the data of high-capacity hard disks. Check "Erasure time" for your reference.

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Q.3 We want to additionally purchase multiple packages of "Disk Shredder 4" for concurrent usage and backup. Can you give me a discount?
If you order 10 pieces or more at once, we give you a discount depending on quantities. For more information on the volume discount, please feel free to contact Sales Division.

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FAQ on the software license agreement of Disk Shredder 4

Q.1 I understand that I run "Disk Shredder4"(FD version) by using a single FD alone. But if I use the same FD many times, won't the FD be damaged sometime in the future?
In the early history of personal computing before a hard disk became popular, many application software ran from FD and we did not get many damage reports. Also, "Disk Shredder4" only reads from the FD and no writing is done. Hence, we feel that there should not be a practical problem unless the disk drive in the customer's PC has some serious physical problem. If you experience a problem in the long run, please see the replacement policy in the following A2. The FD media is a high-quality media that is made in Japan.

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Q.2 Can we make backup copy of FD or CD-ROM before running "Disk Shredder4"?
No. Making copies of "Disk Shredder4"'s FD or CD-ROM is prohibited(including one for the purpose of backup). However, to remedy the problem of media damage, in the case of media damage within one year from the date of purchase(the free warranty period), the sales agency or Personal Media Corporation will replace the damaged FD or CD-ROM free-of-charge(Postage might be charged). For further details, please contact the sales agency or Sales Division of Personal Media Corporation.

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Q.3 Is there any maintenance contract for "Disk Shredder 4"?
If you need more maintenance services than services written in "Disk Shredder 4: Software License Agreement", contact our Sales Division.

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Q.4 While we are waiting for a replacement for a damaged FD or CD-ROM, can't we use "Disk Shredder4"?
The sales agency or Personal Media Corporation try to send out the replacement FD or CD-ROM during its ordinary working hours as soon as the request is received and processed. The delivery time is about one week(or two weeks during the long holiday week, and/or the end of year/new year holidays). However, this is only an approximation and should be adjusted for non-working days and public holidays, mail delivery time, etc. The sales agency or Personal Media Corporation does not guarantee the non-disruptive use of "Disk Shredder4". If your business requires constant backup solution, we recommend you to buy multiple copies of "Disk Shredder4" which will also lead to improved efficiency.

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Q.5 What if we have a bad sector that can not be written into using ordinary software?
"Disk Shredder 4" skips such bad sectors and continues processing. At the end of the processing, "Disk Shredder4" reports the number of such skipped sectors. Please be warned that the data in such bad sectors may not have been overwritten.

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Q.6 I work at a PC rental agency. Is it all right for us to let the customers handle the data erasure themselves? That is, is it all right for us to send "Disk Shredder 4" FD or CD-ROM as well as the PC hardware, and when the rental period expires, we ask the customers to run "Disk Shredder 4" if they want to clean the disk?
No. Disk Shredder 4 License Agreement states in Article 2.3 that: "... in the office where your organization exists." And Article 3.3 also applies in this case. Hence you cannot do this without prior written consent from the sales agency or Personal Media Corporation. However, we have prepared a special licensing terms and conditions for rental agencies like yours. Please contact the sales agency or Personal Media Corporation for details.

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