Sandy, if your installation of Britannica was successful, the problem must have arisen prior to this addition of this new application, as you already suspected. You could try unistalling it & see if that helps. It's all in the nature of the beast - Windows. jv16 Power Tools when started will give you the "clean registry" option among others...Under "tools" it shows all the backups it has made for each time you used the program. Try restoring the next freshest backup and check for changes. Continue doing this till you exhuast all possibilities. Remember you can always use it to clean up anew. It also has a backup tool. Use it. I'm thinking that if when you previously right clicked and chose "properties" for "My Computer" the error surfaced, yet now it does not, then restoring previous backups may perhaps re-enable the entire "properties" functions. The knowledge base for XP will not render any additional info re this problem you are encountering - "RegOpenKeyEx: The handle is Invalid" I've posted to a XP help group and I've indicated to you what they offered, which was the "what else does the event viewer show"? Another participant suggested repairing IE. I don't think that will work, but you can try it. Should something else arise as a possible solution you'll be the second one to know. For the time being you can make do - though this annoyance may be troublesome it doesn't impede your use of XP. Other than that, I can only suggest to do a repair install of XP.(EUCH!) Sorry I couldn't help. And to think M$ is already planning to deploy "longhorn", yet all this is still going on with XP??? It won't be long before they discontinue support for XP too, not that they ever offered much for it anyway. BTW, Longhorn bootleg copies are readily available on the streets of Thailand, should you want to get a copy.(LOL) armando "Sandy O'Neill" <muruagogo@xxxxxxxxxxxxxx> wrote: Re:RegOpenKeyEx: The handle is Invalid Hi Armando and all, Sorry I have not replied sooner but I had no responses from anyone and then bingo they all came in just now, all in one go! Yes I did try to restore a RegCleaner (JV16 Powertools) backup but it didnt work. Mind you, I tried the last backup it did, however I dont really know how long I have had the problem because I dont need to click on properties very often. I was installing Britannica 2004 and I was following the specific instructions to see if I had enough room. That was when I discovered the error message. I do have a bit of further information though. Now, when I right click and chose properties on, say, My Computer, it works properly. On other things, it doesnt work properly, will bring up the error message and then work as normal. So, I dont quite know why it now does that because when I first noticed the problem, it occurred on everything and, of course, the first place I noticed it was on "My Computer". So, whether the RegCleaner backup I used, or whether even the scannow, did something, I dont know. Thanks for everyone's input. And yes, I do also use the Microsoft RegClean. It seems to work okay, hasnt caused any problems that I know of and seems a pretty innocuous little programme (famous last words .... !!). And yes Armando, I use XP Home. Sandy :)