Dell inspiron 1545 lock up after boot up and ran a short timeXP

Have you tried running Dell's diagnostics:
http://www.dell.com/support/diagnostics/us/en/19?&~ck=a...

Yes. Passed memory test but not the harddrive test. Error "Not a Dell recognized harddrive (can't remember exact wording). This is a Dell outlet center unit and the harddrive has been replaced once (this is the 2nd one).

Have you tried a system restore back to a date before problem started?

Yes but the laptop locks up before it is restored. Have t turn power off and then on to start. What I mean for lock up is the mouse curser is locked and can't move it. I am trying to resurrect my old Acer laptop with Windows XP. It was woking when I turned it off sand started using the Dell.

Laptop is working now. It is very strange and turns out to be the wireless router (Linksys N1200) which is also connected to my NetTalk Duo VoIP box. The VoIP phone quit working last night so I restarted it (unplued power and plug power back in), My desktop started working mush faster so I told myself it could be this that caused the laptop not to work, Turned it on and lo and behold it worked again.