Q: bought iphone 6s. tried to synch with itunes but told problem with windows installer package. deleted everything apple except apple installer package that wouldn't delete but still no luck. HELP.

Try reinstalling iTunes. Before installing a fresh version, disable your antivirus.

Also, take a look at the troubleshooting steps suggested here:

Fix unexpected quits or launch issues in iTunes for Windows - Apple Support

If you can't install or update iTunes for Windows - Apple Support

Hope this helps!

Try repairing Apple Software Update from the Programs and Features control panel if it still exists, then reinstall iTunes. Otherwise try the Miscosoft install and uninstall utility mentioned in the notes to the second box.

For general advice see Troubleshooting issues with iTunes for Windows updates.

The steps in the second box are a guide to removing everything related to iTunes and then rebuilding it which is often a good starting point unless the symptoms indicate a more specific approach.

Review the other boxes and the list of support documents further down the page in case one of them applies.

The further information area has direct links to the current and recent builds in case you have problems downloading, need to revert to an older version or want to try the iTunes for Windows (64-bit - for older video cards) release as a workaround for installation or performance issues, or compatibility with QuickTime or third party software.

Your library and device backups should be unaffected by these steps but there are links to backup and recovery advice should it be needed.

tt2