This sounds like a NT hang. I have a similar problem on my NT 4 PC.
Powering off and then powering back on has always cured it.....after which
I will run disk doctor and defrag. Probably something to do with a driver
conflict. I would make sure you have a good backup in case things get
seriously corrupted and update your drivers regularly. Hopefully there will
be a fix eventually.

Mark
[log in to unmask]

>I've got a little P5 system with Tyan 430TX mobo, Pentium 166 MMX,
>64 MB SDRAM, WD 3.2 UDMA HDD. It has been behaving nicely for
>months.
>
>Today I power it up and it performs maybe 75% of the boot and stops.
>Windows NT logo is on the screen. The HDD LED burns continuously.
>No evidence of disk activity (no audible sound, etc.). On the second
>try, it boots OK. I run Norton Disk Doc. on the 1 gb C: and Norton
>sez no problems detected.
>
>If the thang stops loading software and the HDD lite stays on, it
>__has__ to be hardware. Right?? So maybe theres a sporadic and
>hard-to-replicate fault in the HDD??
>
>I'm open to any suggestions, any advice. Does Western Digital have
>diagnostic programs on their site that I should try? Etc, etc.
>
>  TIA,
>  David