NAT32 has very modest processing and memory requirements. Any 1 GHz (or higher) CPU is suitable, and 1 GB of RAM is adequate.
However, the crucial question is: which version of Windows should be used?
Ideally, one of the Windows Embedded versions (Standard 7 or later) should be used, but (unfortunately) Microsoft does not supply such versions to end users. The next best alternative is Windows 7 Starter, but again, not very many end users will have access to that version.
Of course, the still widely available Windows XP could be used, but NAT32 should then be configured to isolate the system's TCP/IP stack from the Internet for security reasons.
Interestingly, the current Windows 10 platform is
not suitable for running applications such as NAT32 that are required to run non-stop. This is because the OS can force updates and restarts to occur at any time, and the user has no control over the procedure. However, NAT32 can effectively prohibit updates by means of its DNS filtering abilities and an appropriate
black list.
Because NAT32 is written in C and requires only the standard C runtime library available on all platforms, it will even run on the open-source Windows alternative
ReactOS. Tests on the currently available ReactOS Version 0.4 look promising, although some issues remain.