Vista - Error in SDT Enlarge Check - Vista Boot Error - Hep Required

Hello,
guys when i boot my computer after the Intel screen show up i see this error couple of times.

Once i inserted Vista DVD boot my pc from it and did repair but it said no problem found then i did Memory Diagnostics and my PC went ok.
When second time i counter this error i just restarted my pc and it went away
Today again i got this error and it went away after performing Memory Diagnostics.
Currently my OS is running fine but am worried about this error as in future it may come again and i can loose my data if i got stuck.

So, if any on you can tell why am having htis strange error and how can i get rid of it then i wld be realy thankful.

thankyou.

My PC's Configuration:
Processor: Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz, 2331 Mhz, 4 Core(s), 4 Logical Processor(s)
OS Name: Microsoft® Windows Vista™ Ultimate
Version: 6.0.6000 Service Pack 0A Build 6000
System Type: x64-based PC
System Manufacturer: INTEL