Erwin
You do not have much spare RAM. If you get Internet Explorer (or other browser) not responding you might try what follows.
If your system is holding on to Standby memory and not releasing it to
Free memory. You can force release by restarting your computer but often this is not very convenient. Another way to force the release of Standby memory is available using RAM Map (freeware from Microsoft):
http://technet.microsoft.com/en-gb/sysinternals/ff700229.aspx
Download and install, and create a shortcut on your Desktop to RAMMap and / or pin to your Taskbar. When you sense the system is becoming unresponsive use Ctrl+Shift+Esc to access Task
Manager. Click the Performance tab and the Resource Monitor button. Click the Memory tab and check whether Free is near to Zero or is Zero. If it is, open RAMMap, click Empty on the Menu bar and Empty Standby list. This action instantly restores
Free memory.
The procedure using RAMMap is an effective workaround but the true solution lies in discovering the source of the problem. Knowing the source you may be able to resolve the problem by
contacting the provider of the software and / or updating the software.