This has been happening more and more over the past couple of years
There are a couple fixes for this issue
1. Disable UAC on the pc - this step is important
2. on older pc's we used to be able to delete the scheduler file and recreate . On newer pc's this file doesn't exist
- Windows 7 and later - C:\ProgramData\ACT\ACT Data
- Right-click the SCHEDULER_FILE.xml file, select Rename. Add .old to the current name (SCHEDULER_FILE.xml.old).
- Close Windows Explorer (or My Computer).
- Launch Act!.Launch
- Act! Scheduler.