Using iScreensaver with Anti-Virus Software

Popular Anti-Virus Packages for Windows

Using Avast for Windows

The first time you download iScreensaver Designer, Avast may try to block the app from running.
The first time launch iScreensaver Designer, Avast will cause problems (causing the Helper App to crash)
The solution is to Allow an exception for iScreensaver Designer, and then close and re-open it
If Avast does not set up an exception, you can add it manually as follows:
Open Avast, choose the Settings icon:
If iScreensaver is not in the list of Allowed Apps, then add it manually:

Using Microsoft Security Essentials for Windows

Under default settings of MSE, no special actions are needed to install a screensaver.

Uninstallation: the screensaver will be deactivated, but it won't actually be removed. (Tested under Win7Pro/x64) If this is the case, then you can remove the screensaver files manually by following these instructions.

Using Kaspersky 2010 for Windows

Dude, Where's My Installer?: Under default settings of Kaspersky, it will block the screensaver installer as a "generic trojan-like behavior." It will then delete the EXE file by moving it into quarantine, which prevents installation.

Solution:

Re-download or unzip the files again.

Open Kapersky.

Click the System Security page.

Click 'Settings' next to 'Application Filtering.'

You will see the Installer listed in the Untrusted or Restricted areas.

Select the Installer.

Click the 'Move To' icon, and choose 'Trusted.'

Exit Kaspersky, and try the installation again.

Uninstallation: the screensaver will not be deactivated, nor will it be removed. (Tested under Win7Pro/x64) If this is the case, then you can remove the screensaver files manually by following these instructions.