Windows Installer Hangs, Tried Most Typical Solutions

This problem happened to me already once a few months ago, and I wish I wrote down how I fixed it now..

I need to install a newer Java, but anything using windows Installer will just hang up at 0% then usually I will have to shutdown processes to even get whatever to close.

I have gone to Services and make sure the msiexec service is running and should run at startup (tried delayed start too).

I have registered and unregistered the service. I have run system file checker and found nothing. I have run some FixIt thing off of MS website.

I think these are most of the typical solutions I have seen suggested when googling, but I could be missing something.

I found this other thread on these forums: Windows Installer - Simple Fix that worked for me.

...but my registry doesn't have the path they are talking about.

I am fine up to HKEY_LOCAL_MACHINE\SYSTEM\CURRENT CONTROL SET\SERVICES\MSIserver (with different capitalization) but then there is no WOW64 subfolder. I am running Win7 64bit with SP1.

I have not tried booting into safe mode or anything like that yet. I think I tried that last time and it didn't work and anyhow I don't want to have to boot into safe mode any time I want to (un-)install stuff.

What else can I do? Thanks so much.