I am trying to upgrade my omnibook 4100 notebook from the original 4 Gb to a 10 Gb .i have done an image onto the 10 Gb , but it will not boot . any ideas ?

Obviously the imaging did not work
You will need to Repair your Windows

Microsoft's Windows XP Professional Repair Install step by step
http://www.windowsxpprofessional.windowsreinstall.com/installxpcdrepair/part3.htm

Microsoft's Windows XP Home Repair Install step by step
http://www.windowsxphome.windowsreinstall.com/installxpcdrepair/part3.htm

Vista Repair:
http://www.windowsreinstall.com/winvista/index.htm
http://vistahomepremium.windowsreinstall.com/repairstartup/repairstartup.htm

You also need to check if your BIOS supports the larger capacity drive. One of the capacity limits of old BIOS'es is 8.4GB... check for an update.

Damn you're right, that's the most likely cause on this old computer

read: http://www.techspot.com/vb/topic36678.html

Great post Tedster!! It may be best to read the thread first though
As for your ongoing URL posts, (without any info attached, I found 4 other irrelevant to the thread posts, as well. ? Just with URLs attached!, I have decided to contact Julio for the third time on this issue of your posting, or BAD posting I should say)
Seeming I found all up 14 posts like this (in the past few days) Maybe time to learn, huh? (seems a shame to post, and then have it removed later on)
Take it as an order. Stop posting like this

That link is about minimum 32Gig issue
We're talking 10Gig here !

andyc's advice is most likely correct