When opening ACT! the window disapears or will be minimized.
there are several reasons for this,
- one could be that you used 2 monitors in the past (so act did store the info to display act on the second monitor)
- you minimised ACT and you did store the preferences.
- a uncontroled shutdown of your pc
you can reset the preferences by opening ACT-Diag
you can find ACTDiag.exe in c:\program files\ACT\Act for Windows\ ActDiag.exe (on 32 bit OS systems) on 64bit you must choose the folder that contains 32bit applications.
in ActDiag, you will see the Tab Tools, and there you will find „Delete Preference Files“ this will reset all settings to the default, and you window should then show again
you may also want to checkout this link