cannot install garmin connect 3.2.26.0

If you're having an issue with 2 PCs then your best bet may be to contact Product Support. You may have an issue with AV or firewall, or perhaps your wifi if you're connecting over wifi? If you are try cabling direct to rule out any wifi issues. Also see this FAQ

https://support.garmin.com/support/searchSupport/case.faces?caseId=%7B68b703a0-2275-11e4-eaba-000000000000%7D

I have read the FAQ, that's not it. Yes, I use wifi like everyone else. I'm not sure I have any cable. Haven't had any problems with my wifi which I have had in the last 8 years.
I also tried to turn off my AVG protection, but that did not solve anything.

Well Express runs fine, and always has, on my Win7 laptop and desktop and my Win8.1 notebook, so it's likely an issue somewhere in your system. If the FAQ hasn't helped then I'd suggest you call Product Support, they can access your PCs remotely to determine the issue.

How large is the download program? I have made the download compatible to win XP and now it is downloading, but it seems to be stuck halfway.

It should download in a few minutes, it's not a large program.

It should download in a few minutes, it's not a large program.

there it is for ½ an hour now.

Then I suspect something in your PC/ISP is blocking the download.

I also tried this one:

1. Press the Windows key+R
2. Type "services.msc" and press Enter
3. Locate and right-click Garmin Core Update Service
4. Click Properties
5. Click on Log On tab
6. Select This account
7. Click Browse
8. Type Network Service
9. Click Check Names
10. Click OK
11. Remove all text from both password fields
12. Click OK
13. Click OK again
14. Right-click Garmin Core Update Service and Click Stop
15. Right-click Garmin Core Update Service and Click Start
NOTE: This is not a permanent fix. These steps must be repeated if Garmin Express is updated to a newer version or re-installed.

But I could not find 'Garmin core update Service' on the list?

The Garmin Core Update Service is dependent on Microsoft .NET Framework, so you may have an issue there. I suggest you uninstall Garmin Express. Try to uninstall it from the Control Panel\Programs and Features first. If you get any error messages use the instructions for Garmin Express toward the bottom of this FAQ

https://support.garmin.com/support/searchSupport/case.faces?caseId={0b668180-4b8e-11de-f35c-000000000000}

In the Microsoft Fixit application, choose "Detect problem and let me select the fixes to apply" then "Uninstalling".

Once you have Garmin Express uninstalled run the Microsoft .NET Repair Tool from this FAQ https://support.garmin.com/support/searchSupport/case.faces?caseId={c9ab5190-3cd7-11e3-f27b-000000000000}

which should correct any .NET Framework issues.

Finally, reinstall Express.

Just seen this which may or may not be your problem

https://forums.garmin.com/showthread.php?182247-Express-install-quot-Failed-Try-Again-quot