from intel's webpage on e7500: http://ark.intel.com/products/36503/Intel-Core2-Duo-Pro...
check the 'instruction set' section. it says 64bit. that means your cpu can run both 32 bit and 64bit instruction. so if you want to install a 64bit operating system, go for it. your cpu can run 64bit os without problem.
Intel® 64 architecture delivers 64-bit computing on server, workstation, desktop and mobile platforms when combined with supporting software.¹ Intel 64 architecture improves performance by allowing systems to address more than 4 GB of both virtual and physical memory.