I am a complete novice at fixing computers but can anyone help.
We had a mother and father of a storm Thunder and Lightning my computre did start after but slowley this morning it just wont power up it trys but just wont boot up Help

Is it giving any signs of life? If not, it's probably just a busted fuse.
More likely the problem lies with the power supply unit. $30 for a new one. No big deal.
Make sure the casing is grouded (via power cabe). Thunderstorms create a lot of static charge which can damage sensible (read: expensive and vital) parts of your system. It's allways wise to shut it down, if you don't have UPS with precharge protection (for modem line too).
Don't go making mistakes like me - defragmenting a drive during storm (suffices to say, it ended with formating) and such.

If you have no picture on your screen could mean smoked VGA or (as mentioned) power supply.

Sometimes it's just a residue charge in the system that needs to be discharged via grouding, but it's a long shot.

Thanks I finally got it started After checking all conections in computer

It has a mind of it's own, doesn't it?