SecProbe.io

April 13, 2007

Room 4561

Mr. Jon Gacek
Executive Vice President, Finance and
  Chief Financial Officer
Quantum Corporation
11431 Willows Road
Redmund, WA  98052

Re: Quantum Corporation
 Form 10-K for Fiscal Ye ar Ended March 31, 2006
 Filed June 12, 2006
 File No. 001-13449

Dear Mr. Gacek:

We have reviewed your response to our letter dated December 4, 2006 in
connection with the above referenced filing a nd have the following comments.  Please be
as detailed as necessary in your explanations.  In some of our comm ents, we may ask you
to provide us with supplemental inform ation so we may better understand your
disclosure.  After reviewing this inform ation, we may or may not raise additional
comments.

 Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filing.  We look forward to  working with you in these respects.  We
welcome any questions you may have about our comments or any other aspect of our
review.  Feel free to call us at the telephone numbers listed at the end of this letter.

Form 10-K for the Year Ended March 31, 2006

Consolidated Financial Statements

Consolidated Statements of Operations, page 50
1. We note your response to prior comment 2 and have the following additional
comments:
• We note that you assigned value to patents having future economic value which you capitalized as purchased tec hnology. Explain in reasonable detail
how you determined the fair value of these patents as well as the patents not
related to the lawsuit an d the undesignated patents;
• Tell us how you allocated the settlement considera tion among the three groups
of patents;

Mr. Jon Gacek
Quantum Corporation
April 13, 2007 Page 2
• You indicate that the two designated pate nts related to the lawsuit are invalid,
and are not needed to protect exis ting or future products. Explain the
relationship of these specific law-su it-related patents to any notion of
settlement of past damages suffered by STK;
• Explain why the “two patents identi fied in the law suit,” have any
capitalizable fair value (based on a third party estimate of fair value) since in
your latest response the two designated patents related to the lawsuit are
invalid, and are not needed to protect exis ting or future products.  If that fair
value related to prior product patent infri ngement with no future benefit tell us
why it should be amortized over future periods as opposed to being expensed
in the period of settlement;
• Your response does not clearly support classification of the amount related to
the settlement as non-operating costs merely because they had no future benefit and were not part of normal opera tions.  We note that the litigation or
law suit related patents were related to  a claim involving some past operations
of Quantum that involved pa tent violations. It appears that the settlement was
agreed to in order to compensate STK for past infringement by Quantum
acquiring technology that, in your view  was immediately impaired with
respect to any future benefit.  The acquired and impaired patent technology
would therefore appear to be operating in  nature that in the company’s view
had no future use.  Please revise to cla ssify these costs as operating expenses
or explain why you believe revision is unnecessary and
• Please explain where any related legal f ees involved in the settlement were
classified and the basis for that classification.

Notes to Consolidated Financial Statements

Note 16: Business Segment Information and Geographic Information, page 77
2. We note your response to prior comment  4 where you indicate that total
undiscounted cash flows attributable to the QSS acquired intangible assets were estimated to be $33.4 million.  Please explain to us how you arrived at the estimated $33.4 million in QSS intangible asset cash flows in view of the
relatively dissimilar historical 2006 conso lidated operating activ ity cash flows of
$3.4 million.
3. Tell us how you considered paragraph 18 of SFAS 144 in determining the number
of future years used in your valuation of intangible assets and how this number
compares to the estimated useful lives of the intangible assets of two to ten years
from the date of purchase as disclosed in Note 5.
4. In view of complying with the guidance in  paragraphs 22-24 of SFAS 142 tell us
why you believe using each of the two va luation approaches is appropriate in
determining the concluded fair valu e of the reporting units and how you

Mr. Jon Gacek
Quantum Corporation
April 13, 2007 Page 3
determined the weighting assigned to each of your Income Approach and Market Approach.
5. Tell us how the valuation assumptions used to derive the concluded fair values are
consistent with other similar assumptions  you used to value other assets, derive
budget and planning estimates, develop compensation arrangements or determine other amounts you disclose.

 * * * * * * *

 As appropriate, please amend your filing and respond to these comments within
10 business days or tell us when you will provid e us with a response.  Please submit all
correspondence and supplemental materials on EDGAR as required by Rule 101 of Regulation S-T.  You may wish to provide us with marked copies of any amendment to expedite our review.  Please furnish a cove r letter with any amendment that keys your
responses to our comments and provides any requested information.  Detailed cover
letters greatly facilitate our review.  Please understand that we may have additional comments after reviewing any amendment and your responses to our comments.

You may contact David E dgar, Staff Accountant, at (202) 551-3459 or the
undersigned at (202) 551-3730 if you have any questions regarding these comments.

Sincerely,

Craig Wilson
Senior Assistant Chief Accountant