BSOD iaStor.sys DRIVER_IRQL_NOT_LESS_OR_EQUAL STOP: 0x100000d1

I use a Dell Dimension 8400 with the original Pentium 4 processor (3.0 GHZ), system purchased 09/2004. I run Windows XP SP 3. The original HD (250 GB SATA) apparently Western Dig (# WD2500JD) uses Loc 1 at board. This HD ran fine up until about 18 months ago when it began to bog down particularly during file searches and expanding the directory in windows explore. Clean-up and defrag did not help, nor did clearing internet cookies, files, etc. I decided that it would be a good idea to install a second internal HD. Seagate 640 GB SATA OEM was installed to location 0 on board about one year ago. I had the “bright idea” of installing the same OS on the new HD so both HDs would be easily accessible for daily use (and if one failed I would have an automatic back-up). In order to increase ease of access to either HD, I installed a program called “Bootmaster” which is a grid pop-up that appears between POST and BOOT and allows the user to select which HD to run. All seemed to work fine until about several months ago during which the new HD began to display BSOD. [I cannot relate this change to any hardware or software changes]. Although still slow, the other (original) HD continues to run without BSOD issues. Initially, the BSOD would appear after hours of running (while internet browsing, using Outlook Express or WORD etc.). The BSOD occurrences have recently increased in F&F (frequency & frustration), most recently to the point that it occurs at every start within minutes after the desktop appears before any applications have opened. About one week ago, after the BSOD presented, the HD started to accelerate like a jet engine out of control. The power button would not turn off the unit. I had to cut the power at the multi-strip. I am still able to run the new HD successfully in SAFE MODE. The details follow:

The problem seems to be caused by the following file: iaStor.sys
DRIVER_IRQL_NOT_LESS_OR_EQUAL
Technical Information:
*** STOP: 0x100000d1 (0x00000010, 0x00000002, 0x00000000, 0xf7542dfa)
DateStamp 0x40608c73
After some research, I discovered that many Dimension 8400 users have experienced the same BSOD with different parameters. (Most of these units, however, were purchased after mine). Dell finally included an item at their support site (http://support.dell.com/support/top...37D4EDB0F8C9893E0401E0A55172362&doclang=en&cs) that implicates the same driver but reveals a different stop code. Microsoft also has an entry at their support site (http://support.microsoft.com/?kbid=839876&sd=RMVP) but with different parameters. I don’t think that either of these solutions would fully address my issue. I found free software at http://www.nirsoft.net/utils/blue_screen_view.html that allowed me to extract the following details from the BSOD technical information (from the Windows minidump folder where BSOD history resides) --
Caused by Driver: iaStor.sys (Intel Application Accelerator driver); address iaStor.sys+edfa
Other files in stack --
• USBPORT.SYS USB 1.1 & 2.0 (Port Driver); C:\WINDOWS\system32\drivers\USBPORT.SYS
• ntoskrnl.exe (Microsoft® Windows® Operating System NT Kernel & System) C:\WINDOWS\system32\ntoskrnl.exe


I am not wedded to the idea of keeping both HDs with an OS. I am not certain of the exact cause but it seems that the most comprehensive solution might be to –
• back up the newer (larger) HD, zero fill and use this HD as a “mirror” HD in a RAID Level 1 (as described in the Dell Owner’s Manual). Before I do this, I’d like some input in relation to precautions and the likelihood of this being the right fix.
Alternatively –
• I wondered if it might be easier, safer and just as complete to delete / roll back / update the implicated drivers. But I’ve heard some horror stories about the removal and renewal of these drivers that I’d rather not deal with. Thank you for any feedback; I am grateful for the shared time and expertise.