Are you trying to find out how much memory is in the computer during the install??
If so, then if there is an option to open a terminal during the install, simply run the following command:
This will give the memory usage info in megabytes (-m). For example, from my installed Lubuntu system:
tom@desktop:/data$ free -m
total used free shared buffers cached
Mem: 3954 3695 258 0 240 1812
-/+ buffers/cache: 1642 2311
Swap: 953 0 953
In the total
column, you see that I have 3954 megabytes of memory, or about 4GB, which is what is in my computer.
The command cat /proc/meminfo
will also list the total amount of memory (in kilobytes) along with a lot of other parameters. For example:
tom@desktop:/data$ cat /proc/meminfo
MemTotal: 4048980 kB
Also, you could open a terminal from any Linux live CD and run those commands to get the memory info.