I would stick with 32 bit for only 3gb RAM. If you want to upgrade your RAM you can consider reinstalling 64 bit which must be done from booted media as 32 bit cannot run 64 bit Windows installation media. But a proper Clean Install would boot the media anyway, deleting all partitions to get it cleanest. See the gold standard install here: http://answers.microsoft.com/en-us/windows/wiki/windows_10-windows_install/clean-reinstall-windows-10-upgradefactory-oem/1c426bdf-79b1-4d42-be93-17378d93e587 If you have performance problems then go over this Checklist to make sure the install is set up correctly, optimized for best performance, and any needed repairs get done: http://answers.microsoft.com/en-us/windows/wiki/windows_10-performance/windows-10-performance-and-install-integrity/75529fd4-fac7-4653-893a-dd8cd4b4db00 But remember that a factory or Upgrade install are inferior installs that most enthusiasts would never run in the first place because they'd expect endless issues. Most prefer to do the gold standard Clean install from this link: http://answers.microsoft.com/en-us/windows/wiki/windows_10-windows_install/clean-reinstall-windows-10-u There is also an automated Windows 10 Refresh which reinstalls Windows while leaving out the factory bloatware that throttles Windows and causes endless issues, and lets you save your files. https://www.howtogeek.com/265054/how-to-easily-reinstall-windows-10-without-the-bloatware/ I hope this helps. Feel free to ask back any questions and let us know how it goes. I'll keep working with you until this is resolved.