running vista with all service packs installed,my problem is when I start the pc from cold will not boot up,if i press the restart button it will boot no problem and works fine any help please

You haven't even said what computer it is!

Sorry newbie at this PC is

MB Gigabyte s series GA-M52L-3SP
OS Windows Vista Ultimate inc all service packs
Avast Anti-Virus
4gb ddr2 800 mem
Graphics Card GeForce GTX 260
CPU AMD Phenom 11 X4 925
Nvidia nForce 10/100mps Ethernet Adaptor
PSU 650 W
Hope this will help

What actually happens when you boot first time? Please go into detail as to exactly what the computer does and doesn't do!

boots to the first part where bar goes across the screen as though its loading then just sits there,if I then press the reset button I will load to my deasktop no problem

I would also like to suggest Advanced Windows Care from Iobit. It's a great program and free, but has an upgrade for a reasonable fee to get extra tools. Also has smart defrag(free), gamebooster(free for standard version). Another thought is making sure that all of your drivers are up to date. I have and Nvidia card and was having similar problems. If it is stopping on boot, it appears that some driver is having trouble being loaded. May just be a simple matter of defragging the drive. The event viewer, aforementioned, may give some insight as to the problem.

De-fragged drive removed my Nvidia card from MB reseated it ,uninstalled and re-installed latest graphics drivers and now all is ok many thanks for the help.