Precautions When Selling, Trading, or Sending a PC to Salvage or to a Repair Shop

 24 May 2007


Sensitive data is confidential, private, personal data on any digital media.  Experience has shown that many if not most PCs to be transferred out of production,  still contain data which is considered sensitive related to University business.  This includes passwords, employee/student private and/or personal data, financial, health, banking information, personnel documents, proposals, contractual records, etc. Thus when a University Microcomputer sent to University Salvage and Surplus, or transferred between departments,  sent for repair, or otherwise disposed of, such sensitive data on any related media should be permanently and securely overwritten or destroyed.

Recommendations for Microcomputers

Since manual removal of individual occurrences of sensitive data has been shown to be unreliably incomplete, this author recommend using a professional disk sanitation algorithm ( ) or wiping tool software that supports DoD 5220.22-M disk overwriting Standard (  to completely overwrite fixed disk(s) of PCs that are being transferred out of production:  sold/traded between departments, or sent to University Salvage and Surplus or sent out for repair.

Methods (detailed algorithms) to completely securely overwrite fixed disks are well documented. For example, see:  .

Other Media and Devices

Finally, in addition to overwriting PC fixed disks, floppy and zip disks, CD's, there are other media that pose privacy/security risks. For example, network devices, like routers, PDA's (hand held Personal Digital Assistants) can have departmental information stored as personal data or configuration information. Prior to transfer or disposal this data or configuration  information should be cleared manually and by someone who understands the device(s) in question.

Related Penn State Policies and References

It is important to note that there is an ongoing official Penn State Committee still working on, and officially organizing, the comprehensive security dimensions of this topic. This web page will be updated when that Committee's official recommendations actually are finalized.

It is also important to work with departmental computer and data people before overwriting data on any PC.  Also review the following Penn State Policies in conjunction with the technical information above:

Policy for Sanitizing University Computer Media Prior to Transfer or Disposal:  (to appear when finalized)
University Archives and Records Management Policies:
University Salvage and Surplus Policies:
Penn State Policies Guidelines and Laws:

Some Available Software

Evidence/Local Activity Eliminator (Windows):  and for the Macintosh, MacWasher:

The following software completely destroys (overwrites; wipes)  ALL data on fixed disk(s), including the operating system.  Actual MS Windows and Linux software that support secure (DoD 5220.22-M disk overwriting Standard) complete wiping of fixed disks may be found at:
Commercial disk wiping software for PC's may be found at:

SuperScrubber:   rewrites a Macintosh hard drive.
East-Tech DiskSanitizer (Windows or Linux fixed disks):
IBM Secure Data Disposal:
Paragon Disk Wiper:
Micro 2000 Disk Eraser:
Wipedisk by Allegro, Inc.:

Solutions for Macintoshes:
For MAC OS 10, boot from the MAC OS 10 Install CD that came with the system;
    Choose the WipeInfo Utility to wipe the fixed drive. This may or may not conform to the DoD Standard.
Norton Antivirus  WIPEINFO utility:
                                   WIPEINFO includes the DoD Standard for disk wiping. This will work for PC's and MAC OS9.
ShredIt is available for Mac OS 7, OS 8, OS 9, OS X as well as for Windows 95, 98, 2000, ME, NT, XP.

Free PC disk wiping software may be found at:
(Any fixed BIOS/firmware hard disk - DoD=yes, Open Source=yes) Darik's Boot and Nuke:
(Any IDE hard disk- DoD=yes, Open Source=GNU) University of Washington Autoclave:
Secure Data Disposal(sdd) - IBM Thinkpad Utility:

Making/copying a PC hard disk image and later restoring it; and disk cloning via  Acronis  True  Image:


Departmental computer professionals, (ultimately Administrative Department heads), have the responsibility to secure departmental, college, and University sensitive data. This responsibility includes following University Policies on Disk Sanitation and data archival, as well as touching base with related department people, and then clearing or overwriting all sensitive data on PC fixed disks and other devices before the they are traded/sold/salvaged/repaired.


Thanks to Pete Weiss and Todd Litzinger(who heads up the on-going Penn State Committee on this topic),  Penn State Administrative Information Services for helping to review and improve this document. Thanks to Bill Verity and Jonathan Siegle, Penn State Information Technology Servicees, for Solutions for Macintoshes. Also thanks to Donna Johnson from Mireth Tecnology Corporation for information on Shredit.