yessir, windows vista (professional edition, 32bit) to be EXACT
Iam assuming you have jailbreaked your phone.
follow the instructions located here: http://hacktheiPhone.com/iPhone_install_ssh_windows.html
that will install the ssh client so you can change the files and such in the phone.
after you have the client installed..
go to this page: http://hacktheiPhone.com/iPhone_install_nintendo_emulator_windows.html
go to step 13 where it starts with logging into the winscp client. once you have logged into it, don't worry about installing the nes.app folder into the phone since you already have it. Just head to the part where it starts talking about roms. its starts at the paragraph: " Now double click the folder" so ctrl+f it for faster transition. follow that and you should be set. once you winscp installed you wont ever have to worry about it again...until
Apple releases an update. Also you can add as many roms as you like. enjoy
If you do not want to do that...use ibrickr:
its very simple. It jailbreaks the phone for you and you can create folders and add files through it.
once you have ibrickr and have jailbreaked your phone..there should be 4 options.. click the "files" option. now you should be on a screen with a iPhone on the side and 2 options upload files and create folder. don't bother with those 2 options yet. look at the iPhone on the right. it should have lots of this listed like "Applications/" "Library/" "system/"... look in that list for the folder called "var/"...its should be in the bottom. click on the folder and you should now be inside it with several other folders... find the folder called "root/" click on that and you should be inside it with 2 folders called "Library/" and "Media/". click on "Media/". Ok now that you are inside the "Media/" folder, this is where the 2 buttons on the left "Upload files" and "create folder" will come in handy. click on "create folder". it will bring up a box which says "Script Prompt: Folder Name", type in "ROMs", EXACTLY HOW I SPELLED IT AND WITH THE CAPITALIZATION AND THE LOWERCASE. hit ok and now you should see on the right in the iPhone that there is a folder called "ROMs". click on that folder and now you should be in it..it will have nothing in it so don't worry about that. click on "Create folder" again and this type make a folder called "NES", again..exactly how I typed it. now the folder should appear on the iPhone on the right. click on the "NES" folder and you should now be in it,again don't worry nothing will be in it. this is where you will be uploading your roms. click on the "Upload files" option and it will allow you to upload now. Just choose whatever roms you want to put in it and you are set. so next time you want to upload roms..just navigate to /var/root/Media/ROMs/NES and upload roms into it. the roms wont work unless you upload them into that exact folder.
don't let the wall of text in the option 2 intimidate you..it is easier then the other one imo lol. GL.