Crash after crash

Hi there...
I've been editing on Sony Vegas Pro 13 64 bit and of late have crash after crash due to low memory when rendering. Then I stumbled across the below -
Can you tell me how to rectify my problem by analyzing this info or I'd be happy to supply additional info. Thx

Log Name: Microsoft-Windows-Diagnostics-Performance/Operational
Source: Microsoft-Windows-Diagnostics-Performance
Date: 29/03/2014 19:53:31
Event ID: 500
Task Category: Desktop Window Manager Monitoring
Level: Warning
Keywords: Event Log
User: LOCAL SERVICE
Computer: XXXXX
Description:
The Desktop Window Manager is experiencing heavy resource contention.
Scenario : The Desktop Window Manager responsiveness has degraded.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> (apparently this info is no longer availalble. I've just tried to view it.)
<System>
<Provider Name="Microsoft-Windows-Diagnostics-Performance" Guid="{CFC18EC0-96B1-4EBA-961B-622CAEE05B0A}" />
<EventID>500</EventID>
<Version>1</Version>
<Level>3</Level>
<Task>4006</Task>
<Opcode>39</Opcode>
<Keywords>0x8000000000010000</Keywords>
<TimeCreated SystemTime="2014-03-29T11:53:31.036518200Z" />
<EventRecordID>1384</EventRecordID>
<Correlation ActivityID="{036CBC60-F800-0004-D1A9-60B8664ACF01}" />
<Execution ProcessID="1888" ThreadID="1816" />
<Channel>Microsoft-Windows-Diagnostics-Performance/Operational</Channel>
<Computer>XXXXXX</Computer>
<Security UserID="S-1-5-19" />
</System>
<EventData>
<Data Name="DisplayDeviceFriendlyNameLength">22</Data>
<Data Name="DisplayDeviceFriendlyName">NVIDIA GeForce GT 640</Data>
<Data Name="MemoryBandwidth">12629500</Data>
<Data Name="MemorySize">4235194368</Data>
<Data Name="Scenario">3</Data>
</EventData>
</Event>