dllhost.exe

Hello everyone.. I hv a laptop of acer 5738 series with 3 GB of ram and 2.0 Ghz, 800 Mhz FSB. It was running good but 3 days before it started to generated an error msg of “Physical memory dum”(blue scrreen) several times. And dllhost.exe is running (as i checked in task manager), sometimes with 2 instances,and it takes more than 2 gb of physical memory.. i m unable to undrstnd that what should i do with this dllhost.exe..!!
Help me plz..and thanx..!!