IF you want to continue using UFT, you will want to update it from the free download (at least to the version 2.8 maintenance release http://www.uftree.com/UFT/UFTProductInfo/TechSupport/maintenance5.htmlhttp://www.uftree.com/UFT/UFTProductInfo/TechSupport/maintenance5.html ); but I believe that the error message you are getting was taken care of in version 2.9 and later issue; which means you'd need to purchase version 3.0 (hard to find since it is now discontinued). Clicking ignore is probably your ownly option for now since you are running a newer/faster computer.
When you took your data from your old computer, you should have backed it ALL up as a sqz file and then you could have opened the file and saved it from your new computer. Just to copy the files will not work as there are links (I'll call them that) that tell the computer to look for files in certain directories. I would suggest that you delete your PROJECT info from the new computer (that is if you still have the old computer and can make a backup); and when you open UFT (like you would be starting a new project), you can go to File/Open/ and locate your project backup and then you'll have it.
Once you have it on your new computer, IF you then decide to go to TMG, it will transfer over beautifully.