i love these questions. i messed up my install of winXP pro and nothing was running right after fudged the registry but i got to thinkin...what if i re-installed without re-installing?confused? don't be. if you can use a dos prompt, you can do what i did and what my brother has done with his win 98 install.
basically what i did was transplant in a new fresh registry. i went into dos usind a win98 boot disk and deleted c:\windows. then i restarted the computer and the XP disc automatically booted into an OS install and re-installed windows. since your using 98, you have to start the install from the command line. all my data was there as i left it and i then had sweet running virgin registry. the only catch is that some programs will have to be re-installed but you'd be surprised that many programs don't need a re-install to run properly!
if you do this, move any personal and non-OS dependant files anywhere in the windows directory to a different folder outside the windows folder.
by the way, IMO - cleansweep is garbage barley worth the install. does nothing but take up space on the hard drive.
note to all:
if you are an NT/2000/XP user that wants a VERY EASY and usefull registry backup utility, i use ERUNT. whenever i want to 'try' out software without risking it leaving junk behind after an un-install, i run this baby and backup up the hives. when i want to restore - it's just a double-click and reboot away. it's such a simple program to use too! keep in mind that it backs up the registy only. you have to delete whatever files those un-installed programs leave behind but its better than useless registry keys lying around.
get ERUNT here >
http://home.t-online.de/home/lars.hederer/erunt