Special Deployment Guidelines for the Update Compatibility Evaluator (UCE)

Applies To: Windows 7, Windows Vista

The Update Compatibility Evaluator (UCE) generates considerable amounts of data when deployed to a large number of client computers. This can lead to issues with the log file share, the ACT database, and the performance of your client computers. Because the UCE log files are six to seven times the size of the log files from other ACT compatibility evaluators, it is strongly recommended that you initially deploy the UCE to 50 computers or less for less than three days to understand the amount of data generated before deploying the compatibility evaluator throughout your organization.

The following best practices apply to large deployments:

  • Host the ACT Log Processing Service on a server primarily dedicated to running the ACT and limit the running of other applications.

  • Ensure your log file share is always accessible for uploads by the computers to which the UCE is deployed.

  • Verify that you have at least 60 megabytes (MB) of free space per computer, for each day you run the compatibility evaluator, in the log file share.

  • Ensure you do not deploy the UCE to computers with less than 1 gigabytes (GB) of free space or less than 256 MB of RAM.

Hard Drive Space Guidelines

The following table provides hard drive space estimates for different upload intervals.

Upload Interval (in Hours) Free Space per Computer per Day (in MB)





8 (default)




Log File Size and Hard Drive Guidelines

The following table provides guidance for the required amount of free hard drive space, based on a three-day deployment and an eight-hour upload interval.

Total Number of Computers Total Size of Log Files (in GB)













Mitigating the UCE Data Load

The UCE generates a considerable amount of data. However, you can mitigate the data load by following these guidelines:

  • Verify that your file share can handle more than 60 MB of log files per computer per day that the compatibility evaluator runs. If this is not possible, you can:

    • Create multiple file shares on different computers, sending the UCE data to the various file shares through different ACT Log Processing Services.


    • Create multiple file shares on different computers, periodically reconfiguring your ACT Log Processing Service to point to the additional file shares.

  • Remove the processed log files from the Processed folder before redeploying the compatibility evaluator.

  • Start with a small deployment of the UCE over a short duration of time, to get an understanding of the size of the log files and the necessary hard drive space.

  • Use "rolling deployments," avoiding simultaneously starting the UCE on the computers to which it was deployed.

Redeploying UCE

You can redeploy the UCE to your client computers as often as you deem necessary. Two possible strategies for deployment are to redeploy the compatibility evaluator:

  • Before the release of security updates. This strategy requires you to deploy the compatibility evaluator prior to the release of security updates. Deployment should start several days before the release, so that there is time to evaluate the security updates and any flagged issues, before deciding whether to install these updates.

  • Whenever your application profile changes. This strategy requires you to deploy the compatibility evaluator whenever a new application becomes part of your enterprise’s profile, or when updates or changes occur to existing applications.


If you redeploy the compatibility evaluator to a computer already running the evaluator, the original version uninstalls and the new version installs and starts. Because deployments are cumulative, the ACT database saves your existing application dependencies from previous deployments indefinitely. Redeployment is a good time to delete your log files from the Processed folder to free up disk space for future files.

See Also


Deploying a Data Collection Package
Phase 1: Collecting Your Compatibility Data
Update Compatibility Evaluator (UCE) Technical Reference