Hard drive.
Your old game saves will be on your old hard drive/ memory unit. If they are on a memory unit then it is a simple issue of plugging the memory unit into the new xbox and copying the old save to the new hard drive. If you have an old hard drive you can plug the old hard drive into the new xbox and play from there. If you want to transfer the saved games from the old hard drive to the new hard drive you need a hard drive transfer cable and follow the instruction to transfer the data from the old hard drive to the new one.
You do need a hard drive to download expansions, but the system won't turn on if you don't have a hard drive, so if you can turn it on without problems, and can play games then you definitely have a hard drive and you are able to download expansions.
The hard drive just pulls away from the top of the console
Turn your console off before fitting a hard drive. Todo otherwise would risk damaging your hardward and even the data on the hard drive.
GIGABYTES
Hard drive capacity can be measured in either gigabytes or terabytes. It depends on the amount of capacity it has. Hard drive capacity usually is defined by the largest unit of storage. For example a 2 TB drive usually is not referred to as a 2,000 GB drive.
Megabytes, Gigabytes or Terabytes.
A modern hard drive is measured in Gigabytes (GB) 1GB = 1024MB (Megabytes)
Usually in GB and they range from 76 to 900 so if you want a really good computer I would shot for about 200 or 300 GB but if you can afford it and you want the best of the best go for a TB withch is (1,000,000,000,000 bytes)
This was a 6.4 GB hard drive.
The original iPod's hard drive capacity was 5GB and 10GB. Future releases saw increases to the capacity the hard drive to accommodate movies, TV shows and apps. Currently, the largest capacity hard drive for an iPod is 160GB, on the iPod Classic.
1mb
1600GB
120 GB is the highest ATA hard drive capacity. There are many models of computers which can handle this capacity. Laptops are designed to handle 120 GB as well.
milliseconds
The maximum capacity of a hard drive dock depends on what dock is used. The capacity can range anywhere from 2.5 Gbps. to 6.0 Gbps on a higher quality docking station.