Ok I offered to help a friends elderly aunty (me and my big mouth), by retrieving the family tree from her old hard drive from her old pc.
I spent a whole day buggering about with it but have finally done it, so hope this may be of help to some people. By no means am I a computer expert so you do this at your own risk but it worked for me.
1. Remove hard drive from old pc, invested in a very useful hard drive caddy/enclosure, available from pc world for £20 or cheaper if you can be bothered shopping around. You may have the file ready on your current pc.
2. Looked for a folder named Sierra, (the name of the company who made the Generations software), opened and looked for a file with a file extension .uds on the old hard drive using the search facility and copied and pasted this to the desktop my laptop, (or somewhere you can find it).
3. Go to www.download.com
and search for a programme called The Master Genealogist, this will open a .uds file and save as a .ged to your desktop
4. Go to http://ancestryuk.custhelp.com/app/answers/detail/a_id/3673/...
and download a trial version of Family tree maker. Open the file you saved from Master genealogist, most genealogy programmes should now open these and can be uploaded directly to the ancestry website for safe keeping at least or invest in a copy of family tree make, I got one from ebay for £7 was well worth the money to create reports etc
To be on the safe side make copies, (copy and paste), of the original file and experiment with those then you will always have your original file in tact.
Hope this helps someone.
Any queries I will try firstname.lastname@example.org