There is no way (except for a mass-edit of the new registry and maybe edit of some additional application-specific configuration files) to "move" your programs to the new install. Go ahead and repair the original install.

Thanks MiniMax - very useful.

I will go ahead with a repair installation of the original - at least I thought I could ! I had a try just now, and the XP Home CD couldn't see the original (faulty) installation any more. It could earlier today (when I stupidly opted for a parallel install). The original c:\windows folder structure is still there, and all the files look sound - but when I ran repair, all I could see was the new (empty !) installation.

Can you suggest how I can persuade the repair routine to see the old, faulty (but much needed) system ?

Not sure. You might want to try booting into the Recovery Console, then use the BOOTCFG /REBUILD command to rebuild the boot-menu in BOOT.INI. It might be that your old install somehow has been removed from there.

http://support.microsoft.com/kb/314058

Thanks MiniMax.

I found a workaround in 'Special Edition - Using Microsoft Windows XP Home' by Robert Cowart and Brian Knittel.

I copied and pasted most of the contents of my old <Documents and settings> folder to the new folder (same name) set up under the new XP installation. This was a surprisingly simple and effective solution, although it didn't manage all of my software. It did pull in some software, favourites and lots of key settings, documents, e-mails etc. You do need to leap around User Accounts a little bit, but it was relatively straightforward.

The only troublesome software is Office Pro, which is throwing up a well-known message - <Microsoft Office has not been installed for the current user>. There is specific help on the Microsoft support site

http://support.microsoft.com/kb/817960/ko

It seems that a reinstall is the only answer.