First essexboy will be at work and is usually on the forums around 7pm UK time, now 2:00pm in the UK.
I'm not sure what you mean by you haven't got ipsec, presumably you mean no ipsec registry key, as you have posted a registry key data but it wasn't ipsec ?
The ipsec.sys file should be here c:\windows\system32\drivers\ipsec.sys (this is a hidden folder so you many not see it), is that is what you are saying you haven't got.
I have XP Pro SP3, so I don't know if my registry key for ipsec would be the same as for XP Home (you don't say what SP you have ?). Hopefully essexboy will know and could use this information if required.
This is the content of the [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\IPSec] key
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\IPSec]
"Type"=dword:00000001
"Start"=dword:00000001
"ErrorControl"=dword:00000001
"Tag"=dword:00000005
"ImagePath"=hex(2):73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,44,00,\
52,00,49,00,56,00,45,00,52,00,53,00,5c,00,69,00,70,00,73,00,65,00,63,00,2e,\
00,73,00,79,00,73,00,00,00
"DisplayName"="IPSEC driver"
"Group"="PNP_TDI"
"Description"="IPSEC driver"
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\IPSec\Security]
"Security"=hex:01,00,14,80,90,00,00,00,9c,00,00,00,14,00,00,00,30,00,00,00,02,\
00,1c,00,01,00,00,00,02,80,14,00,ff,01,0f,00,01,01,00,00,00,00,00,01,00,00,\
00,00,02,00,60,00,04,00,00,00,00,00,14,00,fd,01,02,00,01,01,00,00,00,00,00,\
05,12,00,00,00,00,00,18,00,ff,01,0f,00,01,02,00,00,00,00,00,05,20,00,00,00,\
20,02,00,00,00,00,14,00,8d,01,02,00,01,01,00,00,00,00,00,05,0b,00,00,00,00,\
00,18,00,fd,01,02,00,01,02,00,00,00,00,00,05,20,00,00,00,23,02,00,00,01,01,\
00,00,00,00,00,05,12,00,00,00,01,01,00,00,00,00,00,05,12,00,00,00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\IPSec\Enum]
"0"="Root\\LEGACY_IPSEC\\0000"
"Count"=dword:00000001
"NextInstance"=dword:00000001