I have a ThinkCentre S50 type 8183 and would like to know whether it supports a 64bit OS or not?
Some models with later Pentium 4 CPUs have Intel 64 bit capability which would allow the system to run a 64 bit OS. These models would have the Intel pentium 4 "Prescott"
A quick test to check CPU version by running CPUid program http://www.cpuid.com/
If that program says you have x86-64 support then you should be able to run 64bit OS.