I sent the log via email to support@bitcoinarmory.com.
As noticed, RAM and CPU load are not high and the Windows has some program running : Bitcoin-Qt, Armory, Skype and other anti-virus softwares.

The following is the info from log file:

2014-02-13 16:30 (INFO) -- armoryengine.pyc:809 - ************************************************************
2014-02-13 16:30 (INFO) -- armoryengine.pyc:810 - Invoked: C:\Program Files (x86)\Armory\ArmoryQt.exe
2014-02-13 16:30 (INFO) -- armoryengine.pyc:811 - ************************************************************
2014-02-13 16:30 (INFO) -- armoryengine.pyc:812 - Loading Armory Engine:
2014-02-13 16:30 (INFO) -- armoryengine.pyc:813 -    Armory Version        : 0.90
2014-02-13 16:30 (INFO) -- armoryengine.pyc:814 -    PyBtcWallet  Version  : 1.35
2014-02-13 16:30 (INFO) -- armoryengine.pyc:815 - Detected Operating system: Windows
2014-02-13 16:30 (INFO) -- armoryengine.pyc:816 -    OS Variant            : 7-6.1.7601-SP1-Multiprocessor Free
2014-02-13 16:30 (INFO) -- armoryengine.pyc:817 -    User home-directory   : C:\Users\Admin\AppData\Roaming
2014-02-13 16:30 (INFO) -- armoryengine.pyc:818 -    Satoshi BTC directory : C:\Users\Admin\AppData\Roaming\Bitcoin\
2014-02-13 16:30 (INFO) -- armoryengine.pyc:819 -    Armory home dir       : C:\Users\Admin\AppData\Roaming\Armory\
2014-02-13 16:30 (INFO) -- armoryengine.pyc:820 - Detected System Specs    :
2014-02-13 16:30 (INFO) -- armoryengine.pyc:821 -    Total Available RAM   : 31.98 GB
2014-02-13 16:30 (INFO) -- armoryengine.pyc:822 -    CPU ID string         : Intel64 Family 6 Model 45 Stepping 7, GenuineIntel
2014-02-13 16:30 (INFO) -- armoryengine.pyc:823 -    Number of CPU cores   : 8 cores
2014-02-13 16:30 (INFO) -- armoryengine.pyc:824 -    System is 64-bit      : False
2014-02-13 16:30 (INFO) -- armoryengine.pyc:825 -    Preferred Encoding    : cp1252

I am not sure that this problem is related to the below topic or not:
https://bitcointalk.org/index.php?topic=373287.0

Anyway, I tried to clear mempool.bin as suggest in that topic. Unfortunately, it makes Armory run for a while and keep getting the same error again and Armory stop running  

I already also tested 'ping' to make sure that the connection to the internet is always available. When the Armory crash with the error message, there has no disconnect occurred between Windows7 and the ISP. So, I think the problem is not about the connection to the internet but not sure what the 'BDM' means?
 
Does anyone have any idea how can I make Armory stable on one of my machine?

I found more error after several attempts restarting Armory and let them run for a day. As noticed, the error always occur after received new block.



2014-02-05 02:54 (ERROR) -- armoryengine.pyc:12346 - BDM was not ready for your request!  Waited 20 sec.
2014-02-05 02:54 (ERROR) -- armoryengine.pyc:12347 -   getattr   name: getTopBlockHeight
2014-02-05 02:54 (ERROR) -- armoryengine.pyc:12348 - BDM currently doing: UpdateWallets (98612157)
2014-02-05 02:54 (ERROR) -- armoryengine.pyc:12349 - Waiting for completion: ID= 41032519
2014-02-05 02:54 (ERROR) -- armoryengine.pyc:12350 - Direct traceback
2014-02-05 02:54 (ERROR) -- armoryengine.pyc:12353 - Traceback:
Traceback (most recent call last):
  File "armoryengine.pyc", line 12343, in passthruFunc
  File "Queue.pyc", line 176, in get
Empty
2014-02-05 02:54 (ERROR) -- ArmoryQt.py:4826 - Error in heartbeat function
Traceback (most recent call last):
  File "ArmoryQt.py", line 4799, in Heartbeat
  File "ArmoryQt.py", line 2052, in createCombinedLedger
  File "armoryengine.pyc", line 7278, in getBalance
  File "CppBlockUtils.pyc", line 1172, in getSpendableBalance
NotImplementedError: Wrong number or type of arguments for overloaded function 'BtcWallet_getSpendableBalance'.
  Possible C/C++ prototypes are:
    BtcWallet::getSpendableBalance(uint32_t)
    BtcWallet::getSpendableBalance()

I got the same error "Cannot get tx copy, because don't have full StoredTx!"

Log file opened at 1391416017: C:\Users\Admin\AppData\Roaming\Armory\armorycpplog.txt
-INFO  - 1391416018: (..\BlockUtils.cpp:1582) Set home directory:
-INFO  - 1391416018: (..\BlockUtils.cpp:1604) Set blkfile dir: C:\Users\Admin\AppData\Roaming\Bitcoin\blocks
-INFO  - 1391416018: (..\BlockUtils.cpp:1614) Set leveldb dir: C:\Users\Admin\AppData\Roaming\Armory\databases
-INFO  - 1391416018: (..\BlockUtils.cpp:1570) SetBtcNetworkParams
-INFO  - 1391416018: (..\BlockUtils.cpp:3564) Executing: doInitialSyncOnLoad
-INFO  - 1391416018: (..\BlockUtils.cpp:3604) Number of registered addr: 177
-INFO  - 1391416018: (..\leveldb_wrapper.cpp:127) Opening databases...
-INFO  - 1391416029: (..\BlockUtils.cpp:1695) Total blk*.dat files:                 113
-INFO  - 1391416029: (..\BlockUtils.cpp:1713) Current Top block in HEADERS DB:  283914
-INFO  - 1391416029: (..\BlockUtils.cpp:1714) Current Top block in BLKDATA DB:  283914
-INFO  - 1391416029: (..\BlockUtils.cpp:1715) Current Applied blocks up to hgt: 0
-INFO  - 1391416034: (..\BlockUtils.cpp:1816) First unrecognized hash file:       112
-INFO  - 1391416034: (..\BlockUtils.cpp:1817) Offset of first unrecog block:      35756123
-INFO  - 1391416034: (..\BlockUtils.cpp:1826) First blkfile not in DB:            112
-INFO  - 1391416034: (..\BlockUtils.cpp:1827) Location of first block not in DB:  35756123
-INFO  - 1391416034: (..\BlockUtils.cpp:3646) Fetching stored script histories from DB
-INFO  - 1391416034: (..\BlockUtils.cpp:3690) Reading all headers and building chain...
-INFO  - 1391416056: (..\BlockUtils.cpp:3695) Total number of blk*.dat files: 113
-INFO  - 1391416056: (..\BlockUtils.cpp:3696) Total number of blocks found:   283918
-INFO  - 1391416056: (..\BlockUtils.cpp:3708) Getting latest blocks from blk*.dat files
-INFO  - 1391416056: (..\BlockUtils.cpp:3709) Total blockchain bytes: 15,071,006,966
-INFO  - 1391416056: (..\BlockUtils.cpp:3715) Parsing blockchain file: C:\Users\Admin\AppData\Roaming\Bitcoin\blocks/blk00112.dat
-INFO  - 1391416056: (..\BlockUtils.cpp:3812) C:\Users\Admin\AppData\Roaming\Bitcoin\blocks/blk00112.dat is 50,331,648 bytes
-INFO  - 1391416079: (..\BlockUtils.cpp:3729) Processed 4 raw blocks DB (22 seconds)
-INFO  - 1391416079: (..\BlockUtils.cpp:3758) Starting scan from block height: 0
-ERROR - 1391416662: (..\StoredBlockObj.cpp:1063) Cannot get tx copy, because don't have full StoredTx!

I got the error after I left my computers at night and start to use it in the morning. There should has no activity during the problem occurred.  

I have Bitcoin Qt and Armory (same wallet) running on three computers (two Windows 7 and one Windows connected to the same network.

In Windows 7:
- All the setting is the default on Armory.
- 'Let Armory run Bitcoin-Qt/bitcoinnd in the background' is checked.
- All data directory is default folders.

In Windows 8:
- All the setting is the default on Armory.
- 'Let Armory run Bitcoin-Qt/bitcoinnd in the background' is un-checked.
- All data directory is default folders.


The Armory on Windows 7 always crash (not response) and I have to close and re-open the applications on these two machines. There has no problem with Armory on Windows 8. As I checked there always had the error as below when Armory crash:

---------------------------------------------------------------------------------------------------------------------------------
2014-01-29 04:00 (ERROR) -- armoryengine.pyc:12346 - BDM was not ready for your request!  Waited 20 sec.
2014-01-29 04:00 (ERROR) -- armoryengine.pyc:12347 -   getattr   name: hasTxWithHash
2014-01-29 04:00 (ERROR) -- armoryengine.pyc:12348 - BDM currently doing: Passthrough (83087279)
2014-01-29 04:00 (ERROR) -- armoryengine.pyc:12349 - Waiting for completion: ID= 83087279
2014-01-29 04:00 (ERROR) -- armoryengine.pyc:12350 - Direct traceback
2014-01-29 04:00 (ERROR) -- armoryengine.pyc:12353 - Traceback:
Traceback (most recent call last):
  File "armoryengine.pyc", line 12343, in passthruFunc
  File "Queue.pyc", line 176, in get
Empty
2014-01-29 04:01 (ERROR) -- armoryengine.pyc:12346 - BDM was not ready for your request!  Waited 20 sec.
2014-01-29 04:01 (ERROR) -- armoryengine.pyc:12347 -   getattr   name: hasTxWithHash
2014-01-29 04:01 (ERROR) -- armoryengine.pyc:12348 - BDM currently doing: Passthrough (83087279)
2014-01-29 04:01 (ERROR) -- armoryengine.pyc:12349 - Waiting for completion: ID= 51653993
2014-01-29 04:01 (ERROR) -- armoryengine.pyc:12350 - Direct traceback
2014-01-29 04:01 (ERROR) -- armoryengine.pyc:12353 - Traceback:
Traceback (most recent call last):
  File "armoryengine.pyc", line 12343, in passthruFunc
  File "Queue.pyc", line 176, in get
Empty
2014-01-29 04:01 (ERROR) -- armoryengine.pyc:13289 - ErrorOut var over-represented number of errors!
---------------------------------------------------------------------------------------------------------------------------------

Please anyone suggest that how should I make Armory more stable on Windows 7?

Armory version 0.90-beta
BitcoinQt version 4.8.3