Below is an exact quote from Cacheman's help file. Although your computer and the BIOS will accept RAM values above 512 MB is no guarantee that your operating system will be able to use it. According to Cacheman (they are experts in memory management) Windows 98 will become unstable with RAM values higher than 512MB, therefore Cacheman has a feature which allows you to have more than 512MB installed but limits Windows 98 to use only 512MB - I use it and my system definitely has fewer crashes than when I allow Windows to muck with my full 1GB of RAM. quote: ------------------------------------ Limit available RAM to 512 MBytes This setting limits total available RAM to 512 MBytes. Windows 95,98 and ME does not officially support 512 MBytes at all, with more installed RAM it can become very unstable. If you are using multiple operating systems on your computer and have due to this usage more than 512 MBytes installed it is recommended to check this setting. Windows 95,98 or ME gets no real advantages of more than 512 MBytes anyway. ------------------------------------ endquote Well their English may not be perfect, but I hope this clarifies the issue for some.