I'll admit I'm not an overclocking guru. The only reason I'm trying overclocking is because of that AnnandTech article saying that the Core 2 E6300 can do some wonderful things on stock cooling.

Anyway. So I was slowly increasing the FSB speed from 266 to 300, and it stayed remarkable cool. I slowly increased the voltage to about 1.36V and took the FSB to 301 and rebooted. I got a "BOOT FAILURE INSERT SYSTEM DISK TO CONTINUE." I thought I had screwed up my hard drive, but taking the FSB back to 300 mysteriously made it work again. I used both GRUB and the default Windows bootloaders and got the same errors. Anything I need to do to keep increasing FSB speeds and still load my OS?

Hardware:
Mobo: Biostar 945P-A7A
Proc: Core 2 E6300
HDD: Western Digital Caviar SE16 250GB 7200RPM SATA 3.0GBps
Video: Geforce 7900GS 256MB
RAM: PNY 2GB 667 DDR2 RAM dual-channel

If you need any more information for this, please ask. I'm just surprised I can only get to 2.10GHz. I wasn't expecting to get to the ~2.6GHz they did, but considering the proc is still fairly cool I was hoping for a little more.

In my experience, overclocking isn't worth it. I used to overclock my old desktop with a P4 2.53Ghz and 1GB DDR2-333 (BIOS multipliers: 133:166). Nowadays I can't run them at anything above 1.9Ghz and 200Mhz DDR (100:100) without seeing strange errors.

YMMV, of course. I admit that I wasn't very careful. The RAM doesn't have temperature sensors, either.

You probally need a better motherboard,one designed for overclocking. A good motherboard can lock the PCI and PCI-E bus.
When you overclcock the FSB you are also overclocking the sata controller. Then the sata controller gets too far out of spec and you can no longer see the hard drive.

.. and remeber that overclocking is running the system in a way its not intended and is likely to couse all kinds of wired stuff to happen. so keep important data and overclocking on diffrent computers or make backups

I can only talk about my experiences, as I overclocked a bit for myself and friends in the past.

For the things you have written: I would never increase the Voltage, if your system runs stable with the original voltage! Just go on trying to get more out of it without increasing the voltage, if you get some erros while testing, you can
a) slightly increase the voltage in danger, seriously damaging ur CPU or
b) go back to the last setting which worked stable and stay with them.

In your case, i would stick with 300MHz FSB and would be happy. It´s a small increase of speed which will (most times) not hurt your CPU livetime. But dont forget to do some good CPU checks afterwards! It is also recommed to test the system with warm temperatures in your room ...

By the way, as vomit allready mentioned, i would always go for an good ASUS board if i try to overclock, i had there the best experiences with this company.

Just to tell my old story:
It was a Celeron 633MHz which was running stable @950MHz (with 100MHz fsb) which gave me a nice boost for gaming. Anyways, I was a bit disappinted because a friend of mine had the exact same system but was able to run his CPU stable @ 1270MHz(133MHz). I just wanted to show here, that you can have a lot of luck with your CPU ... but you dont have to

I overclocked my E4300 not very extremely, I was only setting the FSB from 200 to 233 which gave me 2.1GHZ and was mainly resulting in higher system temperatures and noise. But then my PC showed problems in finding the SATA Drive as well. Sometimes. As my system drive is a PATA (IDE), windows was starting properly. When I set the FSB back to 200, everything ran fine again.

There are quite a bunch of overclockers' websites, and all of them say you need special components (at least very fast RAM and a strong PSU) if you want to OC yer machine. Of course not every mainboard runs stable when overclocked. By the way, I've got an ASUS mainboard of course

Thanks for the advice guys. I guess when I really need the performance boost I'll pop in new parts. =p