How do I install AdobeLinguistic.dll onto my computer?

Hi. I've just downloaded Photoshop CS3 onto my PC (Windows 7). When I tried opening it, it says it can't start as AdobeLinguistic is missing from the computer. I've seen many of these questions asked on different sites and none of the answerers give one, single, clear, coherent solution. I've tried following the steps and nothing seems to work. I'm not very computer savvy so I'd appreciate any help you give to be understandable. The main problem seems to be knowing which folders I download it to and finding the right folders.

Here's some of the other sites whose advice I've tried:

http://answers.yahoo.com/question/index?qid=20090114152415AAguEef

http://www.fixya.com/support/t2905062-when_try_install_photoshop_error_comes

http://www.personalcomputerfixes.com/dll-error-fixes/how-to-fix-adobelinguistic-dll-is-missing-errors/

Thanks in advance.