Hi Prem, it may be due to a Microsoft Update. See the following solution from the SolidWorks Knowledge Base:If your upgrade or install was performed after July 15th, 2015 the most likely explanation is a known conflict caused by Microsoft® update KB 3072630 which was released on July 15th, 2015. This update makes changes to the Windows Installer.
You can try their fix as given below:
1. Click 'Start', click 'Run', type "regedit" in the 'Open' box, and then click 'OK'.
2. Locate and click the following subkey in the registry: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Installer.
Note: If this subkey does not exist, create it.
3. In the 'Edit' menu, point to 'New', and then click 'DWORD Value'.
4. For the DWORD name, type "RemappedElevatedProxiesPolicy", and then press 'Enter'.
5. Right-click 'RemappedElevatedProxiesPolicy', and then click 'Modify'.
6. In the 'Value' data box, type "1", and then click 'OK'.
7. Run a Repair of your SOLIDWORKS Installation (S-050527).
8. After the application installs successfully, reset the 'RemappedElevatedProxiesPolicy' DWORD value to "0" to re-enable the security fix for KB 3072630.