Packard bell restarts after seconds willnot boot up

[rich_43uk]

will not boot up
starts for secomds shuts down

 

[ksiemb]

will not boot up
starts for secomds shuts down

You could be dealing with a memory problem (try booting with single strip of RAM), HDD problem (put hard drive in another computer & check for errors) or any number of other issues like corrupt OS, drivers, etc - In which case you should look at Vista Recovery Options.

http://windows.microsoft.com/en-US/windows-vista/What-are-the-system-recovery-options-in-Windows-Vista