Very Important Message (about temp files) Please Read...
if you want to delete a TEMP or any other folder DO NOT delete these folders!! they contain hidden files that you can not see in fe.. if these files are deleted your device could be rendered useless.....
This message has been reiterated many times in the past, but another reminder is always useful. If you do want to clean out temp files, use a utility such as MemMaid or SKTools, or at least do a backup first!
BTW, I've changed your title slightly to reflect the contents of your thread. Vague titles are not as helpful.
Here, here GiGi! I agree, don't monkey around with them your self, that's why the companies created the cleaning utils. I use the big three, MemMaid, SKTools, and Pocket Mechanic. All three are stellar apps!
I wouldn't say useless... A hard reset wouldd bring them back. The only hidden file I've experienced that would cause a minor problem is index.dat in Temporary Internet Files. Depending on your OS that can be recreated using the welcome.exe trick. This trick makes it look like you did a hard reset (you go throgh the initial setup menus), but you lose no data.
Which folders deleted have you heard would brick your device abf?
__________________
Don't Panic!
Bobby
42 Soft-reset is our Friend :
You double tap the windows.exe file in the \windows folder. It then takes you through the Windows Mobile setup wizard, as it would after a hard reset. The difference is, once it's completed, your Axim is still fully intact. It basically resets some of the Windows Mobile default settings.
Regarding your distrust of the cleaning utilities, I've used them for over a year now, and have yet to have a problem with any of them . . .
Tapping on welcome.exe makes it look like you've done a hard reset (brings you to the initial setup screens), but you don't lose any data. It also fixed the "Page cannot be found" message problem if you had deleted index.dat.
You'd need a file explorer like Totla Commander for Pocket PC to see the file extensions. welcome.exe is in the Windows folder on all of our PPC's.
__________________
Don't Panic!
Bobby
42 Soft-reset is our Friend :
A06 BT which works! 
If you do want to clean out temp files, use a utility such as MemMaid or SKTools, or at least do a backup first!
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