Solve : Cannot Delete .tmp files from Catroot?

Windows XP SP3.
God, I've had the afternoon from *censored* trying to do a simple task of installing a new HP Deskjet Printer. Just plug n play, insert installation disk, and bobs your uncle. I don't think so! Nevermind, have finally got it working.
Right, l USE two CLEANERS, CCleaner and Easycleaner by Toniarts. Both are good and each picks up on different things. Have been using them for ages.
Now all of a sudden, since installing the cra**y HP software, Easycleaner comes up saying l have lots of .tmp files in System32\Catroot, and when l try and delete them, both the program and the whole system locks solid.
Have also done a search on all these .tmp files and when l try and delete them, it says Access Denied, file in use?
First of all, in greengrocer language, what is the Catroot Directory, and how can l delete these .tmp files?
THANKS
PS. I haven't tried safemode yet as l'm a bit reluctant to without knowing what the directory does, and why would .tmp files have access denied?
 

that is because it is a system folder, all updates are stored in Catroot2Thanks IRELAND, but that doesn't explain anything to me really!
These .tmp files have just appeared for the first time since l installed the HP printer.
What is the Catroot (or Catroot2) file then. Aren't tmp files made for deleting?
Regards
Hi willythecat, are you any relation to Fritz the cat?
Anyway, I digress.

Give this a try.  It's a boot disk with some utilities that you can use to delete the entire catroot directory.  It's safe to delete as it is only used by Windows Update, and will be recreated the next time you run the update.Why do you need to get rid of .cat files ? ?Thanks Quantos and Patio.
Patio, the reason l want rid is that these have only just started to appear after installing the HP printer software (this'll be another post!). When l run EasyCleaner, it flags them as unwanted files (.tmp) and when l try and delete them, the complete system locks out.Just an update. All my problems started when l changed my Lexmark printer for an HP all in one. Couldn't remove Lexmark, had problems with the Spooler.exe, and when l finally got the HP to work all these strange things started to happen which they never did before. Task Manager also showed both HP and Lex processes running.
Found a great utility that has now stopped all Lexmark activity for good and when l now run EasyCleaner, these .tmp files no longer show up and Easycleaner now works as it used to.
Coincidence, I dunno but the problem seems to have disappeared for now anyway. Until the next time ??
Thanks for looking at the problem.
Regards