how to repair my PC ? pls help

Here are troubleshooting steps to use to try to solve your problems: Computer lags every couple seconds

If this is the original factory pre-installed OS you have the option to recovery to factory condition by running the Recovery Partition or running the Recovery disk(s). However this will reinstall all of the factory bloatware and useless HP utilities which have better versions built into Win7.

Here are tips to clean reinstall to get the best possible install of Win7: re-install windows 7

Lordbob75 said:

flaco said:

Please have the drivers of the computer ready to isntall them before formatting.

You cannot install drivers BEFORE reinstalling the OS, that doesn't work.

~Lordbob

I mean after formatting like ina pen driver or flash drive

Not necessary with Win7, which is mostly driver-complete.

Newer drivers arrive quickly via optional Windows Updates, and by enabling Hardware driver updating: Automatically get recommended drivers and updates for your hardware

Then check for any missing drivers in Device Manager to import from the Support Downloads webpage for your model computer or device.

peterwong said:

the problem is " press any key to boot from dvd " never come up,
the PC just boot & start the harddisk again

the DVD is a bootable DVD, it is a legal version, I paid for this

You need to go to the BIOS and set the DVD reader to be the first boot. I suspect that's why you're unable to boot off the DVD.

Set the BIOS to have the DVD be the first boot device, restart the PC, put the DVD in the drive and the computer should pick up the DVD from there and you can do what you need to do.

Hope this helps.