Hi,
I tried UBCD4WIn on the following configuration:
I Booted with UBCD4Win, having a HD which couldn't boot (was prepared with Ontrack's Disk Manager) and a memory stick. I wanted to copy data from the HD to the stick. BUT, although I could copy the data from the HD (with right click), I couldn't paste them to the stick (paste function was greyed).
Any ideas??

There had been similiar experiences in the past. OEM windows files was used.
Do you use OEM windows source files? Do you have another source files.

What about keyboard?
copy: Ctrl C
paste: Ctrl V

What about two explorer?
Drag and drop a folder.

I made a number of UBCD4WIN builds by pointing the builder at the installed XP OEM installation. This always worked, but I had the same problem with copy and paste failing. The work around for me was to use the unstoppable copier, although this is a bit slow.

I now have several XP retail copies, and I use one these to build UBCD4WIN. Copy and paste is no longer missing. I can't explain the reason, but I am certain that someone can point out the missing components from the OEM install.

If building with XP... you need to use a clean SP1 or SP2 build that has no additional updates or hotfixes applied to it. XP sources that do have the additional updates/hotfixes are known to cause the exact issue mentioned.