The E6700 support 64 bit and you should be able to install 64bit windows with it. You can also find this information from this link.
However you should also check with the manufacturer of the motherboard for OS compatibility.
Thanks for your response! I checked with the mobo manufacturer and it indeed says compatible, so thank you once again!
I currently have a E6750 running Win 7 64bit, and seems to be running great. I would say that your E6700 would be fine also.
Can I ask what motherboards you are both using with your E6700 cpu's
I'm running a DG965MQ motherboard with my E6700...although a compatibility check beforehand was questionable this was the only motherboard accepting this chip with a MicoBTx form factor. I've been running it about a year (since the chip was released) with no problems at all, very happy the setup.