Interview Questions & Answers -Part 1

Greetings!!

Glad that my friends are sending their Articles to publish in Q & A Zone.Here by my friends are sharing their valuable knowledge with you.

The below questions and answers are prepared by my mate Sreejith Bharathan.Very good Q&A to prepare for interviews 🙂

Many thanks Mate . 🙂

1.What are the ADDLOCAL and ADDSOURCE properties?

ADDLOCAL:  It will install the components (file resources) associated with the feature locally on the client the package is installed on.

ADDSOURCE:  The files will be “installed” on the source meaning where the MSI is originally located. There will actually not be any installation of files into the folder but they must exists as “external uncompressed”.

 2.Explain the difference between Property and PROPERTY?

Property: Private Properties in MSI (Properties that cannot be changed during runtime).

PROPERTY: Public Properties (Properties that can be changed during runtime).

3.Use of INSTALLLEVEL Property?

The INSTALLLEVEL property is the initial level at which features are selected “ON” for installation by default. A feature is installed only if the value in the Level field of the Feature table is less than or equal to the current INSTALLLEVEL value. The installation level for any installation is specified by the INSTALLLEVEL property, and can be an integral from 1 to 32,767.

 4.What is the difference between Repair and self healing?

Self Heal and Repair are two different concepts in Windows Installer which people many times consider to be the same thing however there is difference in these two.

Self Heal is triggered by advertised shortcuts, or other advertising information in the package which eventually Repairs the application.

When the application is launched by advertised shortcut, it checks for all the key paths of the Current Feature, if any of the key paths is missing it will launch Repair.

Note that if there are multiple features then it will not check the missing key paths of the other features, but only the feature of which the advertised shortcut is launched.

Repair of an MSI can be triggered by

• Repair button in Add/Remove programs
• Giving the command line msiexec /f{other option} {MSI name}
• Self Heal by advertised shortcut or other advertising information
• Active setup

Once the repair of the package is triggered, even with Self Heal, then the whole of the MSI is reinstalled. Then it does not see that only the feature which triggered the self heal should be repaired, but the whole MSI, by which I mean, all its features are reinstalled.

 5.Custom Action conditions:

Requirement	Condition
Action runs only during install	NOT Installed AND NOT PATCH
Action only runs during removal of MSI	REMOVE~=”ALL”
Action runs during install and reinstall only	NOT REMOVE
Action runs during install and remove	There must be no condition

 6.Product code, Package Code and Upgrade code?

Product Code:

This code should only be changed if significant changes are made to the application – changes that warrant calling it a different product.

You change the product code when:

• The name of the .MSI file has been changed.
• The component code of an existing component has changed.
• A component has been removed from an existing feature.
• An existing feature has been made into a child of an existing feature.
• An existing child feature has been removed from its parent feature.

Note that adding a new feature (top level or child), consisting entirely of new components, does not require changing the product code.

Package Code:

As the name implies, the package code identifies a specific MSI file. I want to emphasize: not a product, but an MSI file. No two MSI files that are not identical copies of each other should ever have the same package code, even if they install (different versions of) the same product. To change the package code, go to the Summary Information Stream panel, put the cursor in the Package Code field, and press the “Generate GUID” button in the lower part of the screen.

Upgrade Code:

All applications in a product family shared the same upgrade code. Such a group of related applications can consist of different versions and different language versions of the same product. You should never change this code, unless you want to prevent major upgrades.

 Summary
When to change the package, product and upgrade codes, and the product version.

Update Type    Package Code      Product Version      Product Code       Upgrade Code Small update        change               don’t change           don’t change        don’t change Minor update       change                   change                 don’t change        don’t change Major upgrade     change                   change                    change                don’t change

 7.Difference between Run, Run Once, Active Setup

Active Setup:

It is used when your application requires installation of components such as files or registry keys on a per-user basis, but application has no advertised entry points or other triggers to initiate the installation process.

Run:

The Run key is processed after every logon, either by the Explorer shell, if it is present, or by First Boot Agent (FBA), if a custom shell, Command shell, or Task Manager Shell is used. If FBA processes this key, it does so after every logon, not during first boot as it normally would. Typically, this flag is used to load Systray applications, launch services in executables, hide autostart applications, or hide background processes

Run Once:

The RunOnce key is processed only once, by FBA, after Plug and Play device enumeration and DLL registration processing have completed. The values of this registry key are deleted from the registry after it is processed, so that it will not run again. Typically, this flag is used when a reboot is required, such as for a DLL or OCX registration, or for cleaning up a setup or an uninstall.

[To be continued..]