I think we need more Information from you.
What Landesk Version? Did you created already the Software Packages?
Has all Systems a Landesk Agent installed? Why are you not able to install?
Normally you push out first the Agents to all Systems and then you create Packages.
After this you make a Scheduled Task and push out your Package to the Clients (always test you package on a Testsystem first).
i already install landesk agent to all clients computers.
now i wanna know that how could i install the software like mozilla firefox to someone client computers.
kindly please provide me steps.
You are asking for a lot in this question as the steps would be very long if you haven't used the product much before.
I suggest you start with some of the online training here : http://community.landesk.com/support/community/training
You need to get familiar with the concepts for software distribution and you will start to see the different ways that products can be deployed. If your company can stretch to some official training that would be very good for you.
If you need information about specific products, www.appdeploy.com is a useful resource on ways to install. Otherwise, get as far as you can and then this community could help you with any errors you encounter.
The One-Stop Shop for LANDesk Enhancements
Here is an Example, how to deploy Java to your Clients:
Software Like 7zip is available as MSI Package, so you can
create a MSI Distribution which is the easiest ways.
For Office and Firefox you can use the Search Function, there are
good Instructions available, but I think it's better to begin
with something that's not so complex.
Hope this is helpful to understand Software Distribution.