Lee

sounds like you have a extra HD installed purely for recovery saved files, this won't be very big and depending on the settings of the recovery system will fill up as you save stuff on main system HD.

solution....
Access recovery settings to make sure its saving only stuff you need saved.
ie: pictures, web favourites.
To view the files on that HD you will prob need to enable hidden files to be shown goto top of the window and select.
Tools > Folder options > then click the view tab, then you will see the option to tick a box to show hidden files.

you will need to be system admin to delete the files i think depending on the recovery system i have no experience of HP one but they are pretty much the same.
After checking the recovery prog is only saving stuff you need it to.
then it will be prob best to delete old saved data or poss overwrite letting the program control it. (only do this if the computer is running fine no point creating a system restore to a unstable point)

other option is like as mentioned have a external HD with loads of space free they are great could not be without mine.