I'm guessing its a problem with Windows Installer. I've tried restarting the service but to no effect. I'm not able to install anything that ends with .msi. Sometimes I get such an error message:
Event viewer logs:
Python installer:
Product: Python 2.7.3 -- Error 1723. There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor. Action CheckDir, entry: _CheckDir@4, library: C:\Users\x\AppData\Local\Temp\MSI570C.tmp
SSDLife installer:
Product: SSDlife Pro -- Error 1723. There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor. Action WIX_TestVersion, entry: WIX_TestVersion, library: C:\Users\x\AppData\Local\Temp\MSIA32E.tmp
Searching on error 1723: This error can occur if you have an out-of-date version of Windows Installer
I got a couple of links for Windows Installer but neither of them has Windows 7 on the list of supported operating systems.
https://www.microsoft.com/en-us/download/details.aspx?id=25 and
Windows(7 x64) is up to date.
Also tried this Fixit: http://support.microsoft.com/mats/Program_Install_and_Uninstall
But it couldn't find any issues.