XP 2x

Here's an idea that could solve problems.
No hard drive is perfect as you know and soon or later some small but necessary file needed for the startup of your OS will get corrupted or worse ...missing.
I lately had a complete "maintenance checkup" being performed to my HDD by a widely acclaimed tool that could do the job (far more extensive than the "chkdisk repair or fix"). It took 5 hours for only 7Gb on my C drive. No problems found.. After a restart I got the message "hal.dll missing... reinstall this item". It was clear that the HD testtool had erased something. Indeed when I rerunned it, it found 1 unrepairable bite. I decided to install another XP on another empty partition of 3Gb. I opened this new second XP OS, went to the dll that was assumed corrupt in the other OS, copied and pasted it in the the original XP, after having removed the corrupt one. To my big surprise the original XP worked again.
Having a second XP OS at your disposal THAT YOU DON'T USE but where you can pick up bits and peaces is far more easier than than the need of a reinstall caused by one corrupt file. Of course this solution won't always work, but in my case it did. And remember you can always have access to data stored on your original OS from within this 2nd one, if something should happen.