X61s (too) slow on boot

[ggiglio]

Hi folks,
my cherished X61s type 7699-3jg 4 Gb ram and 160 Gb sata hdd has become VERY slow on cold boot.
It takes more than 2 minutes (!) after desktop pops out (under win xp sp3) before I can use internet or launch any program other than my computer.
During all this time nothing seems to happen, hdd light is off, cpu usage is at minimum, 27 processes running. Steady state. Then all of a sudden they jump to 40, antivirus, wi-fi and all the other stuff wake up and till next startup the machine runs smooth.
I tried several antivirus software, disabling wi-fi and modem cards, inspecting by autoruns, none of them worked
Scanning the registry for errors didn't hep too. It seems like the machine is waiting for something I can't figure out, until a time out occurs and normal operation begins...
Time to low level format and clean o.s. installation ?
Any suggestion/help greatly appreciated
thanks
Ggiglio

[axur-delmeria]

If you're still using the hard drive that originally came with your laptop, I suggest that you replace it, preferably with an SSD.

[Shredder11]

I would also install the operating system and software fresh to the new SSD, rather than copy the older badly working one across.

[ggiglio]

I agree that swapping the hhd with a ssd is the ultimate solution, but I don't think it could be a hard disk problem.
As I said there is no blinking light on the hdd led during the "zombie time" , so I guess the head isn't searching for a track it can't read.
Anyway, I'll put a wtb request for a ssd with a reasonable price tag.
Yet I would like to know what is really happening under the hood.
Maybe a service invoked at startup (but I didn't find anything suspicious with autoruns).
Maybe a rootkit ?
The usual suspect seems to be windows registry, I can try to borrow a hdd from a working X61 and see what happens.
X61s-X61 shouldn't be a very similar configuration, so I guess it should be just plug'n'play.
What do you think about it ?
thanks
G.