UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

(Rule 13d-102)

Information Statement Pursuant to Rules 13d-1 and 13d-2

Under the Securities Exchange Act of 1934

(Amendment No.         )*

ADVANCED DIGITAL INFORMATION CORPORATION

(Name of Issuer)

Common Stock, no par value

(Title of Class of Securities)

007525108

                                (CUSIP Number)                                

May 20, 2004

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this schedule is filed:

¨ Rule 13d-1(b)

x Rule 13d-1(c)

¨ Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 007525108 13G Page 2 of 6 Pages

1.	Name of Reporting Person S.S. OR I.R.S. Identification No. of above person              Brookside Capital Partners Fund, L.P.              EIN No.: 04-3313066
2.	Check the Appropriate Box if a Member of a Group* (a)  ¨ (b)  ¨
3.	SEC Use Only
4.	Citizenship or Place of Organization             Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH   5.    Sole Voting Power                 3,732,800 shares   6.    Shared Voting Power                 0   7.    Sole Dispositive Power                 3,732,800 shares   8.    Shared Dispositive Power                 0

9.	Aggregate Amount Beneficially Owned by Each Reporting Person             3,732,800 Shares
10.	Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares ¨
11.	Percent of Class Represented by Amount in Row (9)             5.8%
12.	Type of Reporting Person*             PN

Item 1	(a).	Name of Issuer
		The name of the issuer to which this filing on Schedule 13G relates is Advanced Digital Information Corporation (the “Company”).
Item 1	(b).	Address of Issuer’s Principal Executive Offices
		The principal executive offices of the Company are located at 11431 Willows Road N.E., P.O. Box 97057, Redmond, Washington 98073-9757.
Item 2	(a).	Name of Person Filing
		This Statement is being filed on behalf of Brookside Capital Partners Fund, L.P., a Delaware limited partnership (the “Brookside Fund”). Brookside Capital Investors, L.P., a Delaware limited partnership (“Brookside Investors”) is the sole general partner of Brookside Fund. Brookside Capital Management, LLC, a Delaware limited liability company (“Brookside Management”) is the sole general partner of Brookside Investors. Mr. Roy Edgar Brakeman, III is the sole managing member of Brookside Management.
Item 2	(b).	Address of Principal Business Office or, if none, Residence
		The principal business address of each of the Brookside Fund, Brookside Investors, Brookside Management and Mr. Brakeman is 111 Huntington Avenue, Boston, Massachusetts 02199.
Item 2	(c).	Citizenship
		Each of the Brookside Fund, Brookside Investors and Brookside Management is organized under the laws of the State of Delaware. Mr. Brakeman is a citizen of the United States.
Item 2	(d).	Title of Class of Securities
		The class of equity securities of the Company to which this filing on Schedule 13G relates is Common Stock, no par value (the “Common Stock”).
Item 2	(e).	CUSIP Number
		The CUSIP number of the Company’s Common Stock is 007525108.

Page 3 of 6 Pages

Item 3.	If this statement is filed pursuant to §§240.13d-1(b), or 240.13d-2(b) or (c), check whether the person filing is a:
	Non applicable.
	(a)	¨	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).
	(b)	¨	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
	(c)	¨	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).
	(d)	¨	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).
	(e)	¨	An investment adviser in accordance with §13d-1(b)(1)(ii)(E);
	(f)	¨	An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);
	(g)	¨	A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G);
	(h)	¨	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
	(i)	¨	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
	(j)	¨	Group, in accordance with §240.13d-1(b)(1)(ii)(J).
		x	If this statement is filed pursuant to §240.13d-1(c), check this box.
Item 4.		Ownership
Item 4	(a).	Amount beneficially owned
		As of the close of business on May 28, 2004, the Brookside Fund owned 3,732,800 shares of Common Stock of the Company. The Brookside Fund acts by and through its general partner, Brookside Investors. Brookside Investors acts by and through its general partner, Brookside Management. Mr. Roy Edgar Brakeman, III is the managing member of Brookside Management and thus is the controlling person of Brookside Management. No person other than the respective owner referred to herein of shares of Common Stock is known to have the right to receive or the power to direct the receipt of dividends from or the proceeds from the sale of such shares of Common Stock.
Item 4	(b).	Percent of class
		As of the close of business on May 28, 2004, the Brookside Fund was the beneficial owner of 5.8% of the Common Stock outstanding of the Company. The aggregate percentage of Common Stock reported owned by the Brookside Fund is based upon 64,168,782 shares of Common Stock outstanding, which is the total amount of Common Stock outstanding as of January 31, 2004, based on representations made in the Company’s quarterly report for the fiscal quarter ended January 31, 2004 on Form 10-Q filed with the Securities and Exchange Commission on March 16, 2004.

Page 4 of 6 Pages

Item 4	(c).	Number of shares as to which the person has:
		(i) Sole power to vote or to direct the vote: 3,732,800 Shares
		(ii) Shared power to vote or to direct the vote: 0
		(iii) Sole power to dispose or to direct the disposition of: 3,732,800 Shares
		(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of Five Percent or Less of a Class
	Not applicable.
Item 6.	Ownership of More than Five Percent on Behalf of Another Person
	Not applicable.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company:
	Not applicable.
Item 8.	Identification and Classification of Members of the Group
	Not applicable.
Item 9.	Notice of Dissolution of Group
	Not applicable.

Page 5 of 6 Pages

Item 10.	Certification.
	By signing below, the undersigned certifies that, to the best of its knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

Dated: June 1, 2004

BROOKSIDE CAPITAL PARTNERS FUND, L.P.
By:	/s/    Roy Edgar Brakeman, III
	Name:	Roy Edgar Brakeman, III
	Title:	Managing Director