Process Lasso is Windows process automation and optimization software. From tuning algorithms like ProBalance to user-created rules and persistent settings such as CPU affinities and priority classes, Process Lasso enables full control over running applications!

Our famous ProBalance algorithm maintains system responsiveness during high CPU loads. This proprietary algorithm dynamically adjusts the priorities of running programs to keep problematic background processes in check. With ProBalance, no longer will single, or multiple, processes be able to bring your system to a virtual stall. Process Lasso will let you keep interacting with your computer, even when it is under a heavy CPU load.

Process Lasso also allows users to automate and tweak how applications are run through a number of unique and helpful functions. These include persistent priority classes, persistent CPU affinities, disallowed processes, per-process power profiles, a process watchdog for advanced rules, process instance count limits, multiple instance balancing and much more! These features give you the ability to control how programs utilize your computer's resources based on automatically applied settings. With Process Lasso, you can decide exactly how you want your processes to run.

Process Lasso is the ultimate Windows CPU affinity changer. The CPU affinity specifies the set of CPU cores an application is able to execute on. With Process Lasso, you can control this with a persistent setting that applies every time the application is run, or change it dynamically while the application is running once a threshold is met. The CPU affinity is commonly changed to limit CPU use or improve performance.

Many additional functions such as power plan automation, a system responsiveness metric and process activity logging are also available.

For minimal resource use, all algorithms and process rules are enforced by a stand-alone background service called the Process Governor. The GUI is entirely optional.


  • Persist CPU affinities, priorities and more
  • ProBalance priority optimization
  • Proprietary responsiveness metric
  • Rules to act on processes when thresholds exceeded
  • Limit process CPU use
  • Automate power plan switching
  • Disable Hyper-Threading/SMT per-process
  • Balance multiple instances
  • Limit instances of applications
  • Disallow processes from running
  • Keep processes running (auto-restart)
  • CPU affinity changer
  • Keep PC awake
  • Native C++ for maximum efficiency
  • Stand-alone background service applies rules

What's New

  • New load balance algorithm for the Group Extender feature
  • Make effort to enforce CPU affinities on multi-group processes by moving existing threads
  • Tune default ProBalance timing
  • Fix menu-induced config profile switching
  • Assorted fixes and enhancements
  • (23) GUI: Lower default ProBalance time over threshold before action
  • (23) GUI: Add command line parameter /startwithprofile
  • (23) GUI: Add special log entry to indicate reason for continuous reapplication of persistent CPU affinities for multi-group processes
  • (21) GUI: Update French
  • (19) GUI: Add processor group (if specified) to persistent CPU affinities in rules column string
  • (19) GUI: Adjust message about multi-group processes and CPU affinities. A best-effort to move existing process threads is now made, but future threads won't be constrained to the target CPU affinity without re-application of the CPU affinity.
  • (19) Core: Disable Governor log errors when CPU affinity attempted to set on multi-group process
  • (17) Core: Fix issue where Steam services could cause Automatic Game Detection Perf Mode to trigger under some circumstances
  • (15) Core: Add registry option to disable governor minidumps
  • (15) Core/GUI: Fix per-process CPU utilization calculation on systems with multiple processor groups
  • (13) GUI: When 'Show only Process Lasso [systray] icon' used, don't change icon on ProBalance event
  • (11) GUI: Watchdog config dialog: Improve double-click on listview item behavior
  • (11) GUI: Adjustments to solicitation dialog
  • (9) Core: Fix problem with non-default option 'Match command lines' on persistent CPU affinities (this setting is deprecated, use new RegEx matching)
  • (9) GUI: Rules string: move instance count after CPU affinity for clarity when both exist
  • (7) Core: Enable Governor minidumps for release channel
  • (7) GUI: Add confirm/warning about beta channel update frequency when toggled on
  • (7) GUI: Disable 'Main / Elevate Now' menu item instead of delete it
  • (7) Core: Fix a potential governor stop after switching named config profile
  • (5) Core: New method to attempt forcible imposition of procssor group change on multi-group processes
  • (5) Core: GroupExtend: Change methodology to balance thread count across processor groups
  • (5) GUI: Fix GUI wouldn't reload config after named config profile switch by menu item

Features supporting RegEx:

  • CPU Limiter
  • Instance Balancer
  • Watchdog
  • ProBalance Exclusions
  • Support for RegEx will be come to other features in future versions of Process Lasso.