Windows services can't used Interop that is true ?

Dear All,

For my research, i know that windows services can't used Interop for the follow link :

http://stackoverflow.com/questions/13479164/office-interop-does-not-work-in-windows-service

I want to make sure it,can any one get me some detail about this or solve the issue below :

I write an tool to save the PowerPoint slide to image,

you can refer to : http://stackoverflow.com/questions/2972263/ppt-slides-to-images

and it work fine if i start it with an console project.

but when i change it to an windows services , i found that it can't work any more.

the error message :

System.Runtime.InteropServices.COMException (0x80004005): PowerPoint could not open the file.
   in Microsoft.Office.Interop.PowerPoint.Presentations.Open(String FileName, MsoTriState ReadOnly, MsoTriState Untitled, MsoTriState WithWindow)