Just recently I've been unable to install any software on my Windows 7 machine. Anything that uses InstallShield or the Windows installer will just hang or give a weird error.

I noticed there will be many duplicate isbew64.exe processes (like 25) that launch and then just sit there or else a lot of msiexec.exe *32 processes, depending on what I'm trying to install.

One piece of software specifically is the Logitech Harmony software. It gives me an *is_string_not_defined* error, saying c:\program files (x86)\:\ the filename, directory name, or volume label syntax is incorrect.

The other thing I was trying to install was Battlefield: Bad Company 2, and that just hangs as well, and then just leaves all the Windows installer processes running in the background after I quit the install process. Very odd.

I've checked well and googled these issues, it doesn't appear to be any sort of malware issue. I feel like it's related to some kind of corrupted installer application.

I've rebooted, deleted the InstallShield folder in program files/common files as some places online suggested but to no avail.

I have no idea what to do, any ideas?