SECOND AMENDMENT TO LEASE AGREEMNT


This Second  Amendment to Lease Agreement is dated to be effective as of July 1,
1998,  and is made  between  James J.  Laney,  David M.  Laney as Trustee of the
Olivia  Laney Fall Trust,  and Robert W.  Decherd,  Trustee of Laney  Children's
Trusts (the "Landlord") and Allstar Systems,  Inc., a Delaware  corporation (the
"Tenant"

                                    RECITALS

A.   By Lease  Agreement  dated June 24,1992 (the  'Original  Lease"),  Landlord
     leased to Technicomp Corporation and Allstar Services,  Inc. (the "Original
     Tenant")  the land and  building  known as 14202  and  14204  Proton  Road,
     Farmers Branch, Texas, as more particularly described in the Original Lease
     (the "Demised Premises").

B.   The Original  Lease was amended by letter  agreement  between  Landlord and
     Tenant (the "First Amendment").  The Original Lease together with the first
     Amendment Shall hereinafter collectively be referred to as the "Lease".

C.   The Original Tenant assigned its interest in the Lease to Tenant.

D.   The term of the Lease  expires on June 30,  1998,  and  Landlord and Tenant
     desire to extend  the term and to amend and modify the Lease upon the terms
     and conditions set forth below.


NOW. THEREFORE,  in consideration  of the mutual covenants  contained herein and
     for other valuable consideration,  the receipt and sufficiency of which are
     hereby acknowledged, Landlord and Tenant agree as follows:

1.   Section 1.05 of the Lease is hereby amended to extend the Lease Term for an
     additional five (5) years,  commencing on July 1, 1998 and expiring on June
     30, 2003.

2.   Section  1.06 of the Lease is hereby  amended to reflect that Rent shall be
     S10,000.00 per month.

3.   If  Tenant is not in  default  under  this  Lease,  and if  Tenant  pays to
     Landlord the Early  Termination  Payment  (defined below) in the manner set
     forth below,  then Tenant  shall have the right to terminate  this Lease in
     accordance with the following provisions.  Tenant's right to terminate this
     Lease must be exercised by written  notice to Landlord at least one hundred
     fifty  (150)  days prior to the  expiration  of the third year of the Lease
     Term,  or Tenant  shall have  waived its right of  termination.  Time is of
     essence in giving  such  notice.  If Tenant  properly  gives such notice of
     termination, then this Lease shall end as of the last day of the third year
     of the Lease Term (the "Early  Termination Date). The Lease shall terminate
     on the Early Termination Date as if such date were the scheduled expiration
     date of the Lease.


     As a condition to exercising such right of termination,  Tenant must pay to
     Landlord,  at the  same  time  as  Tenant  gives  its  termination  notice.
     Twenty-five   Thousand  and  No/1OO   Dollars   ($25,000.00)   (the  "Early
     Termination Payment).


<PAGE>

4.   Landlord  hereby  consents to  Tenant's  performance  of and Tenant  hereby
     agrees to perform,  certain improvements to the Premises(,) at the Tenant's
     cost except as  otherwise  set forth  herein,  and in  accordance  with the
     provision below (the "Approved  Improvements").  The Approved  Improvements
     are as follows:

     a.   HVAC repair work as more  particularly  describing  in a letter  dated
          June 8, 1998, from West Mechanical to Tenant. Landlord shall reimburse
          Tenant an amount not to exceed Two Thousand  Three Hundred  Ninety and
          No/100 Dollars ($2,390.00) for this work.


     b.   Installation of 4 ton gas heat Arcoaire  package unit in the Northeast
          corner  in  accordance  with  HVAC  Installation  Agreement  with West
          Mechanical.  Landlord shall  reimburse  Tenant an amount not to exceed
          Five Thousand Two Hundred  Forty and No/100  Dollars  ($5,240.00)  for
          such work.

     c.   Five (5) year  warranty and  maintenance  contract on all HVAC rooftop
          equipment  (including the unit described in (b) above) as set forth in
          HVAC Warranty Agreement with West Mechanical. Landlord shall reimburse
          Tenant an amount not to exceed Seven Hundred Fifty and No/100  Dollars
          ($750.00)  per year for such work.  Tenant agrees to keep in force the
          maintenance  contract required by West Mechanical to keep the warranty
          in effect.

     d.   Replacement  of driveway at South side of the Demised  Premises as set
          forth in a  Proposal  dated  June 11,  1998,  from  Charles  Cadenhead
          Construction Company. Landlord shall reimburse Tenant an amount not to
          exceed Eleven  Thousand Seven Hundred  Forty-seven  and 50/100 Dollars
          ($11,747.50) for such work.

     e.   Parking  lot  repairs at 14202  Proton,  as set forth in the  Proposal
          dated  June 2,  1998  from  Charles  Cadenhead  Construction  Company.
          Landlord shall reimburse Tenant an amount not to exceed Eight Thousand
          and No/100 Dollars ($8,000.00) for such work.

          Tenant or Tenant's  contractors shall obtain all necessary permits and
          approvals for the Approved Improvements. Tenant hereby assumes any and
          all liability arising out of or relating to the Approved Improvements,
          including any liability arising out of statutory or common law for any
          and all injuries to or death of any and all persons (including but not
          limited  to  Tenant's   contractors  and   subcontractors   and  their
          employees) and any liability for any and all damage to property caused
          by, or  resulting  from,  or arising out of any act or omission on the
          part of Tenant, Tenant's contractors, subcontractors, and employees in
          the performance of the Approved Improvements.  Tenant agrees to insure
          the foregoing assumed contractual  liability in its liability policies
          of insurance.


<PAGE>


          Landlord  shall  reimburse  Tenant  (am  amount  not to exceed in each
          instance)  the  amounts  set forth [in  subsections  (a)  through  (e)
          above,] only after lien-free final completion of such work and receipt
          by Landlord of proof that all bills in connection  therewith have been
          paid in full and all persons or entities with the right to file a lien
          in connection  therewith  have finally  waived and released their lien
          rights in connection therewith in a manner satisfactory to Landlord.

     5.   Sections 16.1, 16.3, 16.5, and 16.6 of the Lease are hereby deleted in
          their entirety.

     6.   The  Option to  Extend  Term  Lease  Rider is  hereby  deleted  in its
          entirety.

     7.   In all other  respects,  the terms and  provisions of the Lease remain
          unchanged  and the Lease,  as modified and amended  hereby,  is hereby
          ratified,  adopted,  and  confirmed  in all  respects by Landlord  and
          Tenant and continues in full force and effect in  accordance  with the
          terms,  conditions,  and  provisions  thereof as amended and  modified
          hereby.

         SEE EXHIBIT 'A' ATTACHED.

          IN WITNESS WHEREOF, this Second Amendment to Lease Agreement is hereby
          executed as of the day and year first set forth above.

LANDLORD

James J. Laney,  David M. Laney as Trustee of the Olivia  Laney Fall Trust,  and
Robert W. Decherd, Trustee of Laney Children's Trusts.

By:
         James J. Laney

By:
         David M. Laney as Trustee of the Olivia Fall Trust


By:
         Robert W. Decherd, Trustee of Laney Children's Trusts,
         by Patrick B. Mitchell, Attorney-in-fact.

TENANT

Allstar Systems, Inc.
a Delaware corporation

By: \\Donald R. Chadwick
Title:   CFO



<PAGE>


                                   Exhibit "A"

Renewal Option.  The landlord grants the tenant the right to renew its lease for
an  additional  term of  three 3 years at the then  prevailing  market  rate for
comparable  buildings within a two mile radius.  The Tenant must notify Landlord
at least four (4)  months  prior to the lease  expiration  of its  intention  to
renew.

Brokerage Fee: The Landlord agrees to pay The Staubach Company a fee equal to 4%
of the rent due for the  noncancelable  portion of the lease term.  In addition,
the Landlord  agrees to pay The  Staubach  Company a fee equal to 4% of the rent
due for years 4 and 5 provided  ALLSTAR  does not  exercise its right to cancel.
The fee to  Staubach  for the  noncancelable  portion  of the lease  will be due
within 30 days after the Second Amendment is signed by tenant and landlord.  The
fee for the remaining term will be due within 30 days after July 1, 2001.

Allstar Systems, Inc.


By:\\

Donald R. Chadwick
Chief Financial Officer