One thing to try here is to disable all the plugins and then try re-launching the application. Check whether the speed has increased or not? To do so also check the background processes running at the back and observe processes for the time and memory required. You should also try turning off the news feed from the task pane!
You might want to isolate more, check if it is only slow on that specific software or the computer is also loading up slowly. Aside from disabling start up program you can also try to open the software on safe mode this is to check whether the issue is caused by a software conflict or a hardware issue.
In SolidWorks, the load times of add-ins normally should read less than a second. If there is an additional second delay for an unknown reason, this is the time to check. One of the common problems with SolidWorks is a slow startup. In this case, you need to check the load time of your add-ins.
SolidWorks includes a column called “Last Load Time” located on the right of the Add-Ins dialog. There are several reasons for the load time delays of add-ins like unregistered add-in DLL files or your antivirus is currently scanning the DLL file the time the program is loading.
If you experience a slow starting SolidWorks, try adding the program’s installation folder to your antivirus or internet security’s exclusions. If this doesn’t work, uninstall and reinstall that particular add-in.