Q: apple software  update does not work

Please provide sufficient details.

So have you checked your internet settings?

P.S. If you continue to provide as little information as you possibly can, it's unlikely that anyone here will manage to help solve your issue. Are we to guess that you are trying but failing to download iTunes?

Try repairing Apple Software Update from the Programs and Features control panel it it still exists, then reinstall iTunes. If you cannot remove the rump of ASU then you may be able to install the other components individually. I note that there is a new release of Apple Software Update that may mitigate against the issue that some users have had recently updating it, however I cannot find a direct download. With luck it will be baked into the next iTunes installer and iTunes will update more reliably going forward.

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