FOURTH AMENDMENT AND LIMITED WAIVER AND CONSENT TO THE SENIOR SECURED CREDIT AGREEMENT

Exhibit 10.2

EXECUTIVE VERSION

FOURTH AMENDMENT AND LIMITED WAIVER AND CONSENT TO THE SENIOR SECURED CREDIT AGREEMENT

T HIS F OURTH A MENDMENT AND L IMITED W AIVER AND C ONSENT T O T HE S ENIOR S ECURED C REDIT AGREEMENT , dated as of February 14, 2008 (this “ Amendment ”), in respect of and to that certain Senior Secured Credit Agreement, dated as of October 17, 2006, as amended by the First Amendment to the Credit Agreement, dated as of June 5, 2007, by the Second Amendment to the Credit Agreement, dated as of September 11, 2007 and by the Third Amendment to the Credit Agreement, dated as of February 4, 2008 (as further amended, modified, restated, amended and restated and/or supplemented from time to time, the “ Credit Agreement ”), by and among S ILICON G RAPHICS , I NC . , a corporation formed under the laws of Delaware (the “ Parent ”), and certain of the Parent’s Subsidiaries identified on the signature pages thereto, as borrowers (such Subsidiaries, together with Parent, are referred to hereinafter each individually as a “ Borrower ”, and collectively, jointly and severally, as the “ Borrowers ”), the other Credit Parties thereto from time to time, as Guarantors, the lenders party thereto from time to time (the “ Lenders ”), M ORGAN S TANLEY S ENIOR F UNDING , I NC . , a corporation formed under the laws of Delaware (“ Morgan Stanley ”), as administrative agent for the Lenders (in such capacity, together with its successors and assigns, if any, the “ Administrative Agent ”), as revolving agent for the Revolving Lenders (in such capacity, together with its successors and assigns, if any, the “ Revolving Agent ”), and M ORGAN S TANLEY  & C O ., I NCORPORATED (“ MS& Co. ”) as collateral agent for the Secured Creditors (in such capacity, together with its successors and assigns, if any, the “ Collateral Agent ”). Capitalized terms used in this Amendment and not otherwise defined shall have the meanings set forth in the Credit Agreement.

RECITALS:

W HEREAS , the Borrower intends to enter into that certain Stock Purchase Agreement dated as of February 14, 2008, among the Parent and the purchasers party thereto (the “ Stock Purchase Agreement ”) and into that certain Bill of Sale, dated as of February 14, 2008, among the Parent, as buyer, LB I Group, Inc., as collateral agent for certain secured parties, and the other parties thereto (the “ Bill of Sale ” and together with the Stock Purchase Agreement, the “ Acquisition Documents ”), pursuant to which and in accordance with the terms and conditions therein the Borrower intends to acquire selected assets of Linux Networx, Inc., a Delaware corporation (“ Linux ”), in exchange for up to 390,000 shares of Capital Stock (the “ Linux Acquisition ”);

W HEREAS , the Borrowers have requested that the aggregate principal amount of the Term Loans be increased from $127,500,000 to $132,500,000;

W HEREAS , the Administrative Agent, the Borrowers, the Required Lenders and each Lender making a Linux Incremental Term Loan Commitment (as defined below) are willing to consent to this Amendment pursuant to, and subject to, the terms and conditions set forth herein.

N OW , T HEREFORE , the parties agree as follows:

SECTION 1. Definitions. Capitalized terms used in this Amendment and not otherwise defined shall have the meanings set forth in the Credit Agreement.

SECTION 2. Amendments to the Credit Agreement. The Credit Agreement is hereby amended as follows:

2.1 Article I, Section 1.03(a) is hereby amended and restated by deleting the section in its entirety and replacing it with the following:

“ (a) Loan Commitments. Subject to the terms and conditions set forth herein, each Term Lender hereby severally agrees to make a term loan to the Borrowers (i) in the principal amount set forth opposite each such Term Lender’s name on Schedule B hereto to the Borrower on the Closing Date (each an “ Initial Term Loan ”), (ii) in the principal amount set forth opposite each such Term Lender’s name on Schedule C hereto to the Borrowers on the Effective Date (each an “ Incremental Term Loan ”) and (iii) in the principal amount set forth opposite each such Term Lender’s name on Schedule D hereto to the Borrowers on the Linux Effective Date (each a “ Linux Incremental Term Loan ” and together with the Initial Term Loans and Incremental Term Loans, the “ Term Loans ”), in each case in accordance with this Section 1.03 . The aggregate principal amount of the Term Loans to be advanced shall not exceed one-hundred-thirty-two million five-hundred thousand Dollars ($132,500,000). Amounts repaid or prepaid under this Section 1.03 may not be reborrowed.”

2.2 Article I, Section 1.03(e) is hereby amended by deleting the table in its entirety and replacing it with the following:

2.3 Article IV is hereby amended by adding the following new Section 4.04 as follows:

“Section 4.04. Conditions Precedent to the Linux Incremental Term Loans. The obligation of each Lender to make the Linux Incremental Term Loans requested on the Linux Effective Date shall be subject to the satisfaction, or waiver by the Administrative Agent of each of the following conditions precedent:

(a) Authority. The Administrative Agent shall have received certified copies of all resolutions, certificates or other documents evidencing other necessary corporate action and governmental approvals, if any, with respect to the authorization for the execution, delivery and performance of each Loan Document by a Credit Party and for the consummation of the transactions contemplated thereby. All certificates shall state that the resolutions or other information referred to in such certificates have not been amended, modified, revoked or rescinded as of the Linux Effective Date.

(b) Loan Documents. The Administrative Agent shall have received, on or before the Linux Effective Date, counterparts of each of the following documents duly executed and delivered by each party thereto, and in full force and effect and in form and substance reasonably satisfactory to the Administrative Agent:

(i) this Agreement (including any amendments thereto);

(ii) the Notes, if any;

(iii) such corporate resolutions, certificates and other documents as the Administrative Agent reasonably requests; and

(iv) all other documents and legal matters in connection with the transactions contemplated by the Agreement (including any amendments thereto) shall have been delivered, executed, or recorded.

(c) No Change in Condition. There shall not have occurred any event, circumstance, change or condition since March 31, 2006, other than the filing of the Bankruptcy Petition, which could reasonably be expected to have a Material Adverse Effect.

(d) No Legal Impediment. No injunction, writ, restraining order, or other order of any nature (whether temporary, preliminary or permanent) restricting or prohibiting, directly or indirectly, the extending of such credit shall have been issued and remain in force by any Governmental Authority against any Borrower, any Agent or any Lender, and such extension of credit shall not violate any requirement of applicable law.

(d) Consents, Etc. Each Credit Party shall have received all material consents and authorizations required pursuant to any material contract with any other Person and shall have obtained all material Permits of, or approvals from, and effected all notices to and filings with, any Governmental Authority as may be necessary to allow such Credit Party lawfully (A) to execute, deliver and perform, in all material respects,

their respective obligations under the Loan Documents to which each of them is, or shall be, a party and each other agreement or instrument to be executed and delivered by each of them pursuant thereto or in connection therewith, (B) consummate the transactions contemplated hereunder and under the other Loan Documents (including the making of the Incremental Term Loans) and (C) create and perfect the Liens on the Collateral to be owned by each of them to the extent, in the manner and for the purpose contemplated by the Loan Documents. Each Credit Party shall have received all shareholder, governmental and material third-party consents, licenses, approvals or evidence of other actions, necessary in connection with the execution and delivery of the Loan Documents, and the performance thereunder and the transactions contemplated by the Loan Documents, and any applicable waiting period shall have expired without any action being taken by any Governmental Authority that could restrain, prevent or impose any material adverse conditions on such Credit Party or such transactions or that could seek to restrain or threaten any of the foregoing, and no law or regulation shall be applicable which in the reasonable judgment of the Administrative Agent could have such effect.

(e) Solvency. Immediately after the incurrence of the Linux Incremental Term Loans on the Linux Effective Date, and after giving effect to such Linux Incremental Term Loans, and use of the proceeds of the Loans, the Credit Parties, taken as a whole, shall be Solvent.

(f) Opinions of Borrower’s Counsel. Within ten (10) business days after the incurrence of the Linux Incremental Term Loans, the Borrowers shall deliver to the Lenders, and the Lenders shall have received the opinion of Weil, Gotshal and Manges