|Apparently the Pure Networks Platform Service is something that is loaded when Network Magic has been installed.|
If your internet connection works fine, you could Un-install Network Magic, (in Control Panel - Classic View - Add or Remove Programs) and you'll no longer have the problem.
If your internet connection does NOT always work fine, that could be why it's sometimes not starting. E.g. If you're connecting to the internet wirelessly, if you have problems with that, you may have problems with the service starting. Even if you aren't, it's common for a wireless internet connection to not work for a short time after you have first started up Windows, but then it does work - if the service attempts to start up before the wireless internet connection is actually working, that may be the cause of that error.
If you want to continue to use Network Magic, you could try un-installing it then installing it again.
Support for Network Magic
"The Pure Networks Platform Service Is Not Running"
NOTE - that tells you to download the Windows Installer Cleanup Utility.
It has a link but it may not work.
Microsoft is no longer offering the Windows Installer Cleanup Utility on their web site because they have found it causes problems when it is used if Microsoft Office 2007 or later, or any of it's programs, e.g. Outlook ( Outlook Express is not part of Office), Word, PowerPoint, Excel, etc. is on the system, I assume when you use it to un-install those programs.
If you do not have Office 2007 or later or any of it's programs installed, the Windows Installer Cleanup Utility is perfectly safe to use.
You can still download it from places on the web other than on the Microsoft web site.
Download the Windows Installer Cleanup Utility here:
Click on the dark blue Download link at the left.