Extremely slow XP boot

[Ur_Mom]

I am working on a machine at work, and it has a difficult problem. When booting, it starts as normal, then goes to a black screen for 20 minutes, then logs into Windows just fine and is fast from there. The same thing happens in Safe Mode.

I used BootVis to monitor the startup, and everything is extremely fast, but what is holding it up is the Registry + Page File. That is what takes 20 minutes to load. While this is happening, the CPU (Core i3 2.93 Ghz) runs at 100% usage and there is NO hard drive activity (according to BootVis).

This is a Windows XP Pro SP3 machine. I've disabled the page file, no difference (re-enabled after). I've defragged the registry to be sure (SysInternals utility), as well as using CCleaner for a cleanup (yeah, snake oil, but I'll try anything with this). I've disabled hibernation. Chkdsk comes back with no errors.

My last options are to try a SFC /scannow, and a memory scan. If those come back clean, then I'm really stumped.

If anyone has any suggestions or has come across this as well, please reply. I've seen other instances of it happening, but only ~20-30 seconds, not minutes... This machine is very quick otherwise. Once everything is loaded, it hauls ass. BTW: It's a work computer on a domain (does this with or without network connection).

 

[GushpinBob]

Could be hardware related. Are you sure that the hard drive might be failing? *EDIT* nvm, saw that you mentioned chkdsk, though you might wanna run WD data lifeguard or whatever your HD manufacturer provides for diagnosis to be sure.

Also, try booting the machine with only one or two sticks of memory at a time. I've experienced a similar phenomenon with an old P4 machine running Vista. It had 4GB RAM and literally took over 5 minutes to boot on a good day. I could not figure out what on earth was wrong before retreating to the "Vista = dog shit on older hardware" mindset. Lo and behold, I pulled out 2 sticks of RAM and the thing starts from POST to desktop a little over a minute now.

 

[Ur_Mom]

I'll try replacing the memory, but it's a stock Lenovo machine. Haven't opened it up to see how many sticks it comes with. Probably 2.

I'll give it a go though, and see how it goes!