win7 crash

The first dump file blames your ATI video drivers. As such, this can (most likely) be an issue with the drivers or the video card.

To start, please remove all ATI stuff from your system using Control Panel...Programs...Uninstall a program.
Then download and install the appropriate ATI Display Driver (only the Display Driver - not the entire Catalyst Control Center) from the ATI website ( Advanced Micro Devices Inc. )
Then monitor to see if that has fixed the BSOD issues.

If the BSOD's continue, check to ensure that the video card isn't overheating, that it's getting enough power, that the vents aren't plugged with dirt/dust, and that it's fan is working. If all that is OK, then try another video card. If it's a laptop, blow out the vents with canned air (don't use a vacuum cleaner or air compressor as they can damage the components).

Summary of the BSOD's:

Code:

Built by: 7600.16385.amd64fre.win7_rtm.090713-1255
Debug session time: Sat May  1 19:54:39.081 2010 (GMT-4)
System Uptime: 0 days 0:21:41.111
BugCheck 100000EA, {fffffa8005b45b60, 0, 0, 0}
*** WARNING: Unable to verify timestamp for atikmdag.sys
*** ERROR: Module load completed but symbols could not be loaded for atikmdag.sys
Probably caused by : dxgkrnl.sys ( dxgkrnl!TdrTimedOperationBugcheckOnTimeout+37 )
BUGCHECK_STR:  0xEA
PROCESS_NAME:  System
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
Built by: 7600.16385.amd64fre.win7_rtm.090713-1255
Debug session time: Sat May  1 19:32:10.407 2010 (GMT-4)
System Uptime: 0 days 0:17:26.437
BugCheck 100000EA, {fffffa8005a8b060, 0, 0, 0}
*** WARNING: Unable to verify timestamp for atikmdag.sys
*** ERROR: Module load completed but symbols could not be loaded for atikmdag.sys
Probably caused by : dxgkrnl.sys ( dxgkrnl!TdrTimedOperationBugcheckOnTimeout+37 )
BUGCHECK_STR:  0xEA
PROCESS_NAME:  System