Tools-->Options


in RUN tab check the option "Allow mercury products to run 
tests and components" once if u do this u can run ur script 
through QC.

I have not much idea on this but sharing what i had read on 
a expert blog, please see if it helps:

'''From http://hisudhakar.spaces.live.com/blog/cns!
8DDF980C45482279!441.entry

'''' Ref:: http://qtp9.blogspot.com/2007/10/running-
automation-scripts-on-remote.html

By default when you can able execute QTP scripts on a Local 
Machine. Automation Object Model is providing a facility to 
execute QTP scripts on a Remote Machine.

When you use CreateObject("QuickTest.Application"), it is 
giving permissions to execute scripts in local machine’s 
QTP.

To execute scripts in Remote Machine use 

Set qtApp = CreateObject("QuickTest.Application", "Remote 
Machine Name")

Before using this statement ensure that the Distributed COM 
(DCOM) Configuration Properties of the remote computer are 
set to allow you to run QuickTest Professional Automation 
from your computer.

Steps to Set the DCOM Configuration Properties on Remote 
Machine

On the computer where you want to run the automation 
script, choose 
Start--> Run. The Run dialog box opens.

Enter DCOMCNFG and click OK. The Distributed COM 
Configuration Properties dialog box or the Component 
Services window opens (depending on your operating system) 
and displays the list of COM applications available on the 
computer.
Select QuickTest Professional Automation from the list and 
open the Properties dialog box for the application. (Click 
the Properties button or right-click and choose Properties, 
depending on your operating system.)
In the QuickTest Professional Automation Properties dialog 
box, click the Security tab.
In the launch permissions section, choose the custom option 
and click Edit.
Use the Add and Remove options to select the network users 
or groups for which you want to allow or deny permission to 
launch QuickTest Professional via an automation script. 
When you are finished, click OK to save your settings.
Repeat steps 5 and 6 for the configuration permissions 
section to select the users or groups who can modify 
QuickTest Professional configuration options via an 
automation script.
In the QuickTest Professional Automation Properties dialog 
box, click the Identity tab and select the interactive user 
option. 
Click OK to save the QuickTest Professional Automation 
Properties settings.
Click OK to close the Distributed COM Configuration 
Properties dialog box or the Component Services window.

thanks jay prakash for giving the reply but what u suggested
is possible only when that remote machine have qtp installed
on it .My problem is to execute the qtp script on the remote
machine which do not have qtp installed on it .So is there
any way to run qtp script on such remote system which do not
have qtp installed on it .If there then plz let me know .I
hope now  u will get exactly wat i want