Windows XP. Web pages loaded fine, but every time I downloaded a program the download completed, and then instead of installing said "Interupted: Blocked. I have now identified this is being caused by Opera's popup blocker.
Right click on Opera in the start menu.Select >Internet Properties. Select Privacy page. Untick "Turn on pop up blocker. restart computer. Programs can be downloaded again!
If you can't open .msi files go to www.howtogeek.com for clear instructions.... Run > Open type cmd Command prompt screen appears... type msiexec /unregister press return type msiexec /regserver press return and restart computer... problem solved!