Merci

Only thing I came afoul of once, was a
full clean with ccleaner or bleachbit, only to realise my search history, autofill and passwords were all deleted. You can uncheck any boxes of things you don't want deleting in the settings very easily, but that was a slight annoyance for me as I blindly just clicked 'clean' without reading the instructions first, as it were.
Search history deletion wasn't the worst thing, though

oh, and another thing which is the most useful think in the whole world - and will probably target your slow startup issue more than anything - msconfig
Type this in to run / search bar, click the 'startup' tab, and uncheck anything you don't think should be there. All sorts of junk appears, say, like the program for viewing pics you accidentally install when you install digital camera software, java updater, the driver for the printer that broke two years ago, etc.. you can safely uncheck everything in the list (but that will include your antivirus, of course) so just use common sense, get rid of all the obvious useless ones. If unsure, just google the name of the task. Should sort you out nicely
