Looking for tools to diagnose PC H/W problem during boot up

Hello,

I have a PC w/ ASUS P5B-VM motherboard + Core 2 Duo E4300 CPU & XP Professional installed as OS.

These days, I couldn't boot the PC normally. Different boot fail scenarios were encountered below:

1. Boot up process stayed in default ASUS BIOS screen or
2. Boot up (Normal) process always couldn't go further after Windows XP logo appeared or
3. Boot up (Safe Mode) process sometimes couldn't go further after boot commands executed i.e. only text cursor shown in upper left corner of screen or

Yet, command line mode boot up succeeded (but I'd only tried this option once so I didn't whether it succeeded every time. Besides, even boot up succeeded, it took 10 to 20 minutes to complete.

I saw no hardware failure message on screen no matter Windows boot up succeeded or failed.

I want to re-install Windows XP but I also like to diagnose the hardware (e.g. CPU, RAM, motherboard...) before I procceeds with OS re-installation.

Could anyone suggest what software tools available to boot up PC from floppy or CD/DVD drive and diagnose PC hardware at the same time?

Tks!