Hi,
not knowing the peripherals of my computer being compatible to Windows 7 I installed Windows 7 as second OS besides Windows XP on drive C. Using a boot manager I am able to choose the OS alternatively.
Having deinstalled one program in Windows XP I started  - as usual -  RegVac Registry Cleaner and afterwards A1Click.
But this resulted in a desaster. Checking Windows 7 I could not start two of the in Windows 7 installed programs. Most of the program data had vanished.
So I had to reinstall them.
I suppose that these two superwin programs (RegVac and A1Click) don't work properly if there are two OS on one drive.
Hans-J. Cordes

   RegVac only cleans the active registry so if you are running WinXP, it will only clean the WinXP registry and will not touch the Win7 registry.
   A1Click on the other hand cleans all of the drives present which I am sure includes the drive that Win7 is on.  I do not know why it would cause a problem with two of your programs in Win7.  If you look at the Cleaner Settings, it tells what it removes.

Hi Ray, I much appreciate your answer. Up to now I didn't check the items of A1Click completely confiding in your program. Now I will check the shown items every time in the future.
Hans-J. Cordes

I also used both programs in Win 7. I could no longer boot and had to reinstall. Up to then I had no problems. I no longer use programs.

Before you use any of our programs in Windows 7, you need to update them and make sure you have the latest versions.

Just adding my 2 cents I have Win. XP, and Linux installed in my computer and I use RegVac, and A1 cleaner all the time for a long time and everything runs beautifully, no ill effects.  

Hi, that may be, but I have got news. Last time when I started A1Click in Windows XP I lost A1Click in Windows 7. Therefore I decided, not necessary for ever, to stop start using A1Click until I have deinstalled Windows XP.
rawana75