I'm sure most of you have read loads of postings about different errors causing SOD. I have spent most of yesterday TRYING to find relevant help but I'm struggling. I've started having different stop errors and thought I may have found the problem event to post the detail on and then a new one appeared today. The first was DRIVER_IRQL_NOT_LESS_OR_EQUAL with parameter 1 0x05ac0018, 2=0x00000016,3= 0x00000000, 4= 0xf6a4183f. The only event error was id:7000 from the service control manager about a parallel port driver service failing to start because it was disabled or had no enabled devices:

Details
Product: Windows Operating System
Event ID: 7000
Source: Service Control Manager
Version: 5.0
Symbolic Name: EVENT_SERVICE_START_FAILED
Message: The %1 service failed to start due to the following error:
%2.

Then today I had:

Product: Windows Operating System
Event ID: 1003
Source: System Error
Version: 5.2
Symbolic Name: ER_KRNLCRASH_LOG
Message: Error code %1, parameter1 %2, parameter2 %3, parameter3 %4, parameter4 %5.

Explanation
A blue screen (Stop error) was reported. The message contains details about the error. A matching event with Event ID 1001 might also appear in the event log. This matching event displays information about the specific error that occurred.

The SOD read stop error 0x000000d1 (0x00009004,0x00000002,0x000000000, 0xee65df0c)

I am not technically proficient so unfortunately you will have to treat me like a child.

So far I have downloaded a registry fix program and cleaned that up, downloaded belarc and found that I have a seagate hard drive. Then I REBOOTED with seatools and it said bad or missing command interpreter please enter a valid filename when scanning the virtual driver. I have down a memory test using the packard bell snapsys diagnostic and the message was:
[test]
[name]RAM Test[/name]
[problem]Ram error[/problem]
[/test]

What do I do now??
Please, please help
p.s It is a laptop if that makes a difference.
If that is not a Packard Bell machine www.memtest86.com has a free, bootable RAM tester. Try that.

If the RAM is OK, we can proceed from there. If not, that is the starting point.

You have done your homework well. What are the specifics of the machine? How old?

What preceeded all of this? Is it non-functional now? You said you ran a registry cleaner. Why?Thanks for the reply GX1_Man.
I have the following information which I hope will give you a better picture. Unfortunately it is a packard bell laptop so I guess no memtest then?
I realised what the problem was with seagate as I hadn't disabled the drivers for my internal cd disk drive (which gave up the ghost about 14 MONTHS after buying the machine, I now use an EXTERNAL freecom drive). This stopped the command interpreter problem.
After disabling the drivers the and rebooting the seagate ran and I did the advanced scan which came up with the following errors:
Bad sector LBA: 14084905
Bad sector LBA: 14216134
It offered to try and repair the bad sector but or now I chose no.
The system info for my computer is :
OS Name      Microsoft Windows XP Home Edition
Version      5.1.2600 Service Pack 2 Build 2600
OS Manufacturer      Microsoft Corporation
System Name      BABYHATTON
System Manufacturer      Packard Bell NEC
System Model      EasyNote M5xx
System Type      X86-based PC
Processor      x86 Family 15 Model 2 STEPPING 9 GenuineIntel ~2664 Mhz
BIOS Version/Date      Insyde Software Corporation V1.06, 13/11/2003
SMBIOS Version      2.3
Windows Directory      C:\WINDOWS
System Directory      C:\WINDOWS\system32
Boot Device      \Device\HarddiskVolume2
Locale      United Kingdom
Hardware Abstraction Layer      Version = "5.1.2600.2180 (xpsp_sp2_rtm.040803-2158)"
User Name      BABYHATTON\DAN
Time Zone      GMT Standard Time
Total Physical Memory      512.00 MB
Available Physical Memory      103.20 MB
Total Virtual Memory      2.00 GB
Available Virtual Memory      1.96 GB
Page File Space      1.10 GB
Page File      C:\pagefile.sys

I don't think much of the above is relevant.
The problem started last December and as the event id 7000 kept showing up I thought it had something to do with that. The windows error reporting thought it might have something to do with a faulty or poorly written driver.
The computer is still functional it chrashed twice yesterday. I ran the registry cleaner because I am a layman and thought it might help. The machine is about three years old I think.
Hope you can help.
Thanks