Expanding Memory Limits (Optional Large Address Aware Tweak)
When prompted for an installation path, accept the default C:\Program Files (x86)\... path, or create a custom root directory like C:\Games\ or C:\ClassicClient\ to bypass strict Windows UAC (User Account Control) restrictions. Configuration and Compatibility Tweaks classic client 6.3.12 for 64 bits
Deploying Classic Client 6.3.12 on modern 64-bit systems presents several distinct hurdles for system administrators. Expanding Memory Limits (Optional Large Address Aware Tweak)