Re: Java issues.
You shouldn't have v6u26 or u31 as the current but no longer supported is v6u43, but you should have uninstalled u26 when you updated to 31.
If you still have v6u31 showing in Progs & Features, then you could use the free or trial Pro version of Revo and do the uninstall in Safe Mode with Networking.
If it's no longer listed then you could try the reinstall of it from here - it's well down the list.
Reinstall v7u17 when successful and Java have this troubleshooting check list should you still have problems.
Rather than disabling your AV as it suggests, do the installs in Safe Mode with Networking as well, as your AV will be isolated in this mode but will still keep you safe.
You shouldn't have v6u26 or u31 as the current but no longer supported is v6u43, but you should have uninstalled u26 when you updated to 31.
If you still have v6u31 showing in Progs & Features, then you could use the free or trial Pro version of Revo and do the uninstall in Safe Mode with Networking.
If it's no longer listed then you could try the reinstall of it from here - it's well down the list.
Reinstall v7u17 when successful and Java have this troubleshooting check list should you still have problems.
Rather than disabling your AV as it suggests, do the installs in Safe Mode with Networking as well, as your AV will be isolated in this mode but will still keep you safe.