That would only explain the Couldn't write... errors, but not the Unregistring errors.
My guess is insufficient user rights. In XP home edition you have to be logged on as administrator to get it work properly... Though normally it shouldn't even start if you are not logged on as administrator.
Do you always get just these errors
Couldn't write "(App)Start Menu Ordering" setting in INI file!
Couldn't write "(App)OpenOffice 2.0" setting in INI file!
Or do you get a whole bunch of other write errors too? If so add in the portable.ini in [PORTABLE] section value ReadOnlyMode=1
Also could you run Portable CCleaner in debug mode (run the exe with /PDEBUG parameter or change the debug mode on with the portable.ini file) and post the log (you can copy the log text by right-clicking it) in this topic.
I really want to get this problem solved before next Portable CCleaner release. I made a special portable.exe build what will always run in debug mode and it haves extra logging capabilities. So esponjacinzenta please try this build.
Just unzip the exe file in the same directory with all the other Portable CCleaner files and run it. It will create two log files (install.log and portable.log) in the same directory with the exe file. Attach the log files to your reply here or send them to my email *yoink* Thank you.
Anyway to make this working in BartPE off of a CD? Possibly have it copy the files needed modifying to ram drive and executing from there. Then on exit remove temp files. Current portable.exe gives a cclistbar error and exits.