BSOD / Freeze up. Dell - 7 beep error after crash

A "stop 0x124" is fundamentally different to many other types of bluescreens because it stems from a hardware complaint. Stop 0x124 minidumps contain very little practical information, and it is therefore necessary to approach the problem as a case of hardware in an unknown state of distress. You can read more on this error and what to try here... Stop 0x124 - what it means and what to try: Stop 124 - What it means and what to try

Dumps....

Code:

Built by: 7601.18205.amd64fre.win7sp1_gdr.130708-1532
Debug session time: Sun Aug 18 10:21:37.892 2013 (UTC + 6:00)
System Uptime: 0 days 0:01:05.953
BugCheck 124, {0, fffffa8007976028, be000000, 800400}
*** WARNING: Unable to verify timestamp for ntoskrnl.exe
*** ERROR: Module load completed but symbols could not be loaded for ntoskrnl.exe
Probably caused by : GenuineIntel
BUGCHECK_STR:  0x124_GenuineIntel
PROCESS_NAME: NOT FOUND
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Tue Aug  6 06:36:47.425 2013 (UTC + 6:00)
System Uptime: 0 days 0:23:17.861
BugCheck 124, {0, fffffa800799d028, be000000, 800400}
*** WARNING: Unable to verify timestamp for ntoskrnl.exe
*** ERROR: Module load completed but symbols could not be loaded for ntoskrnl.exe
Probably caused by : GenuineIntel
BUGCHECK_STR:  0x124_GenuineIntel
PROCESS_NAME:  System
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Mon Aug  5 06:05:17.482 2013 (UTC + 6:00)
System Uptime: 0 days 16:17:32.919
BugCheck 124, {0, fffffa80065de028, fe000000, 800400}
*** WARNING: Unable to verify timestamp for intelppm.sys
*** ERROR: Module load completed but symbols could not be loaded for intelppm.sys
Probably caused by : GenuineIntel
BUGCHECK_STR:  0x124_GenuineIntel
PROCESS_NAME:  DCS.exe
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Sat Aug  3 07:26:55.957 2013 (UTC + 6:00)
System Uptime: 0 days 0:06:38.393
BugCheck 124, {0, fffffa80079aa028, be000000, 800400}
*** WARNING: Unable to verify timestamp for HCW85BDA.sys
*** ERROR: Module load completed but symbols could not be loaded for HCW85BDA.sys
Probably caused by : GenuineIntel
BUGCHECK_STR:  0x124_GenuineIntel
PROCESS_NAME:  System
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Sat Aug  3 06:33:13.480 2013 (UTC + 6:00)
System Uptime: 0 days 20:39:25.916
BugCheck 124, {0, fffffa80065bf028, be000000, 800400}
*** WARNING: Unable to verify timestamp for HECIx64.sys
*** ERROR: Module load completed but symbols could not be loaded for HECIx64.sys
Probably caused by : GenuineIntel
BUGCHECK_STR:  0x124_GenuineIntel
PROCESS_NAME:  System
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``

Upload the new dumps..
what else have you followed from the 124 guide?

If your PSU is the original Dell it's probably OK, they tend to underrate theirs. 350W would be ample any way.
I did see in your specs you have one 2GB and one 1GB of RAM, that can be a problem. Try removing the 1GB stick and see how it goes. I would recommend getting a new 2x2GB matched kit.

Run memetst86+ for at least 8 passes.
Some hardware tests to run.


RAM (memory) test:

This will require memtest on a bootable CD or USB stick.
RAM - Test with Memtest86+

Windows memory diagnostic tool isn't very comprehensive.

It is the same Stop 124..