SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

(Rule 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED

PURSUANT TO RULE 13d-2(b)

(Amendment No. 5)¹

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(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)

¨ Rule 13d-1(c)

x Rule 13d-1(d)

The information required in 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).

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LeapFrog Enterprises, Inc.

6401 Hollis Street, Suite 150

Emeryville, CA 94608

Hampstead Associates, L.L.C.

Knowledge Universe LLC

Lowell J. Milken

Michael R. Milken

1250 Fourth Street

Santa Monica, California 90401

See Item 4 of each cover page.

Class A Common Stock, par value $.0001 per share

52186N 10 6

Not applicable.

Hampstead Associates, L.L.C., a Delaware limited liability company (“Hampstead”), beneficially owns 11,579 shares of Class A Common Stock that are issuable upon conversion of 11,579 shares of Class B Common Stock, which Hampstead holds directly. Knowledge Universe LLC, a California limited liability company (“KU”), is the manager and a member of Hampstead, and in

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such capacities may be deemed to have the power to direct the voting and disposition of, and to share beneficial ownership of, any securities owned of record by Hampstead.

Lowell J. Milken beneficially owns 315,137 shares of Class A Common Stock of the Issuer, which he holds directly, and beneficially owns 521,335 shares of Class A Common Stock that are issuable upon conversion of 521,335 shares of Class B Common Stock, which he holds directly. Mr. Lowell Milken also may be deemed to be a controlling person of Hampstead and KU and in such capacities may be deemed to have the power to direct the voting and disposition of, and to share beneficial ownership of, any securities owned of record, or beneficially owned, by each of Hampstead and KU, but disclaims such beneficial ownership.

Michael R. Milken beneficially owns 601,789 shares of Class A Common Stock, which he holds directly, and beneficially owns 3,064,937 shares of Class A Common Stock that are issuable upon conversion of 3,064,937 shares of Class B Common Stock, which he holds directly. Mr. Michael Milken also may be deemed to be a controlling person of Hampstead and KU and in such capacities may be deemed to have the power to direct the voting and disposition of, and to share beneficial ownership of, any securities owned of record, or beneficially owned, by each of Hampstead and KU, but disclaims such beneficial ownership.

The persons named in Item 2(a) of this Schedule 13G may be deemed to be a group with respect to the securities of the Issuer which they hold directly or indirectly. Such persons disclaim such group membership.

See Item 11 of each cover page.

(i) Sole power to vote or direct the vote:

See Item 5 of each cover page.

(ii) Shared power to vote or direct the vote:

See Item 6 of each cover page.

(iii) Sole power to dispose or direct the disposition of:

See Item 7 of each cover page.

(iv) Shared power to dispose or direct the disposition of:

See Item 8 of each cover page.

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Not Applicable.

See Item 4 above.

Not Applicable.

See Attachment A.

Not Applicable.

Not Applicable.

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SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

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ATTACHMENT A

Hampstead Associates, L.L.C., a Delaware limited liability company, Knowledge Universe LLC, a California limited liability company, Lowell J. Milken, an individual, and Michael R. Milken, an individual, may be deemed to be a group under Section 13(d) of the Securities Exchange Act of 1934 (the “Exchange Act”) with respect to the securities of the issuer. Such persons disclaim such group membership. The filing of this statement shall not be deemed an admission that, for purposes of Section 13 of the Exchange Act, or otherwise, a Reporting Person is the beneficial owner of equity securities covered by this statement or any other statement that are beneficially owned, directly or indirectly, by any other person.

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EXHIBIT INDEX

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