If your Compaq NX 7400 laptop can read the USB drive, you can install them, but you cannot boot to the USB drive without a bootdriver.
What you posted does NOT have all Compaz NZ 7400 drivers. It has one: "This package contains the driver for the Texas Instruments PCI (TI-PCI) 6x12/7x12 Cardbus (Media Card Reader) for the supported notebook models and operating systems."
I doubt anyone on this forum has the time that it takes do perform what needs doing. You need a friend, or a tech, who can sit beside you with a CD disk or USB download of all the Compaq files.
However, I doubt that you can do what you wish, because a Windows XP Compaq version simply will not allow you to make the changes. It is not the USB drive Idea, but the battle with overwriting windows files and directories that is the problem. If you have files on the USB device that are actually designed to make the repairs or changes, that is another matter... Then there is the matter that you do not have the experience necessary to make this change.
If you do not have the Compaq Windows XP recovery or install disk, and the Compaq is not too old,
Www.HP.com will sell you a new one for about $30 including shipping... if the laptop is registered to your friend.
What is more, do you KNOW what changes need to be made?
I suspect that Compaq, left on, has impact damage that occurred some time after you finished watching the movie during that 12 hour period when it was left on. Irreversible hard drive impact damage could have occurred during that time.
However, with the previously discussed USB external enclosure, you can perhaps recover the data, dragging and dropping it to the new hard drive.
Look at
www.directron.com,
www.newegg.com,
www.zipzoomfly.com,
www.outpost.com,
www.frys.com,
www.cdw.com,
www.pcmall.com or others of your choosing to buy the USB enclosure and a new hard drive.
The other option would be to reformat the hard drive, once you have saved the important data, and use the Compaq restore or recovery disk to reformat and reinstall Windows. After that, you can reinstall your software, then the files that you have saved to the USB drive or enclosured drive.