P4 3.06 HT vs. Celeron D 3.2 & mobo swap

Which is better? I have a MSI MS-6577 motherboard with FSB 400/533 & Socket 478, so these CPU's are my best options. Does the Hyper-Threading technology of the Pentium 3.06 really increase performance past the 3.20 GHz rating of the non Hyper-Threaded Celeron?

Also, I understand that you need to reinstall Windows when you swap motherboards, but my Windows XP was factory installed on a partition of the factory hard drive and I don't think I can access it, unless I am doing a system restore and that won't help with a mobo swap. Is there a way I can upgrade my mobo without buying another Windows XP?

Here are some specs for a comparison on both CPU's:

Intel® Pentium® 4 Processors 3.06 GHz

sSpec Number: SL6S5
CPU Speed: 3.06 GHz
PCG:
Bus Speed: 533 MHz
Bus/Core Ratio: 23
L2 Cache Size: 512 KB
L2 Cache Speed: 3.06 GHz

Package Type: 478 pin
Manufacturing Technology: 0.13 micron
Core Stepping: C1
CPUID String: 0F27h
Thermal Design Power: 81.8W
Thermal Specification: 69°C
VID Voltage Range:

Supported Features: Hyper-Threading Technology

Intel® Celeron® Processor Family 3.20 GHz

sSpec Number: SL7NY
CPU Speed: 3.20 GHz
PCG:
Bus Speed: 533 MHz
Bus/Core Ratio: 24
L2 Cache Size: 256 KB
L2 Cache Speed: 3.2 GHz

Package Type: 478 pin
Manufacturing Technology: 90 nm
Core Stepping: E0
CPUID String: 0F41h
Thermal Design Power: 73W
Thermal Specification: 67°C
VID Voltage Range: 1.25V-1.4V


Thanks to all who read this.