I have become unable to install any files ending .msi. I have tested several of the 197 msi files on the system and none work. I have tried the following:
1.Ran sfc /scannow - no change
2.tried all fixes for error 1607
3.reinstalled Windows installer
4.Downloaded Installshield 10.5 again and unzipped. the msi file. Will not run.
5. gave installshiled full control using Regedit.
I have Windows XP Home with SP3 but there is no security tab available in properties.
What is blocking access to msi files and how do I reinstate the missing security tab?