Packard Bell NEC iMedia 1508/N: BIOS update needed

[Libertarian-too]

I wish to upgrade the current 3.06GHz/533MHz CPU which is non-Hyperthreading to a 3.8GHz/800MHz P4 HT SL7Z3, which the Gigabyte site/manual indicates is compatible with the mobo.
The machine has Award version 10v BIOS which has no means of enabling Hyperthreading, so I need to update the BIOS to an HT-supportive version so that the HT attributes of the replacement CPU can be recognized/utilised.
 
PB no longer offer any support for this model and I am just going round in circles looking for a copy of the BIOS upgrade.
 
Any factual input, especially a copy of the relevant BIOS update (version 20U?) or a (live!) link to download it would be very gratefully received. Alternatively, is there a patch for the current version which would enable Hyperthreading?

Main details as below:

Model: Packard Bell NEC iMedia  1508/N
Model Type: UTOW – 8UN
MS WHQL  No: 8UN 957446
PID: 0488533
P/N: PB43213001
MIM:
Current Operating System: Windows 7 Professional 64-bit SP1
Original Operating System: Win XP Home Edition
System Manufacturer: Packard Bell NEC
System Model: Packard Bell NEC PB13212701
System Name: 00000000000000000000000
System Version: PB13212701
SNID 041411720075
Chassis No. 50524E
Board: NEC COMPUTERS INTERNATIONAL GA-8I915PM (LGA Socket 775)
Mobo is marked Gigabyte GA-81915PM 40A254 00725
Northbridge Intel i915P/i915G rev. B1
Southbridge Intel 82801FB (ICH6) rev. 03
Chipset: Intel 2580 Rev 4
Chipset Model: i915P/i915G
Chipset Revision B1
Southbridge Vendor Intel
Southbridge Model 82801FB (ICH6)
Southbridge Revision 03
Super IO: ITE 8712F Rev 7 at port 002E
SMBIOS Version: 2.3
BIOS chip is labelled Phoenix D686 Phoenix 1998 20090956
BIOS firmware:
System BIOS version: Award Software International, Inc. 10v 11/21/2004
POST Screen: 11/21/2004 i915P – 6A79VG0DC-00
Interface Type: Single PATA IDE channel + 2 SATA channels


Support Information:
Device Type: BIOS / Motherboard
Manufacturer: Packard Bell NEC
Model: Packard Bell NEC iMedia 1508/N Desktop
Interface: Other
Operating System: Windows 7 x64
Age of Device: >8 years old