You've spent a lot of time tweaking your AutoCorrect entries, and now you're getting a new computer. Don't waste time re-creating your those entries -- just copy them from one system to the other.
Working day to day, you've probably built quite a list of AutoCorrect entries. They help you work more efficiently and for the most part, your list is probably unique to you. Not only are the entries unique to you, that list is unique to your local system. That means if you work on another system or get a new computer, you have to rebuild your list -- well, not exactly.
The good news is that you can back up your AutoCorrect entries and take them with you. Run a search using Windows Find File feature for files with the ACL extension -- *.acl. Copy those files to a floppy, CD, or even a USB flash drive. Then, copy those files to the appropriate location on the new system. I recommend that you rename the existing .acl files rather than just overwriting them. That way, you can revert to the existing .acl files if necessary. This is particularly important if you're temporarily using someone else's system. You don't want to overwrite their entries with yours.