FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
BRITTS WILLIAM C
   2. Issuer Name and Ticker or Trading Symbol
QUANTUM CORP /DE/ [QTM] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
EVP, Sales & Marketing
(Last)
(First)
(Middle)
C/O QUANTUM CORPORATION, 1650 TECHNOLOGY DRIVE, SUITE 800		 3. Date of Earliest Transaction (Month/Day/Year)
04/15/2010
(Street)

SAN JOSE, CA 95110		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 04/15/2010   M(1)   50,000 A $ 1.46 696,243 D  
Common Stock 04/15/2010   S(2)   50,000 D $ 2.795 (3) 646,243 D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Non-Qualified Stock Options (4) $ 1.46 04/15/2010   M     50,000 08/22/2006(5) 08/22/2010 Common Stock 50,000 $ 0 139,024 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BRITTS WILLIAM C
C/O QUANTUM CORPORATION
1650 TECHNOLOGY DRIVE, SUITE 800
SAN JOSE, CA 95110		       EVP, Sales & Marketing  

Signatures

 /s/ Josie Buensuceso, by Josie Buensuceso Attorney in Fact for William C. Britts   04/16/2010
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Reflects the exercise of the stock options listed in Table II of this Form 4.
(2) The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 26, 2010.
(3) The sale price reported in column 4 of Table I represents the weighted average sale price of the shares sold ranging from $2.78 to $2.80 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the reporting person will provide full information regarding the number of shares sold at each separate price.
(4) These options were granted under the 1999 Stock Incentive Plan of Advanced Digital Information Corporation ("ADIC") and assumed by Quantum Corporation ("Quantum") on August 22, 2006, pursuant to the Agreement and Plan of Merger between ADIC and Quantum. The options were exchanged for options to purchase Quantum stock, at the exchange ratio of 5.9756 per share.
(5) The options are fully vested and immediately exercisable.

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