Is the new checking account anyway related to the old checking account? If not, then make a new account in Quicken and set it up for downloading. The old account isn't going anywhere unless you decide to delete it for some reason (I wouldn't).
The limit on the number of accounts in Quicken is fairly high, so unless you have created hundreds of accounts over the years, there is no reason to re-use the account.
@Dbaker450 - what version of Quicken are you running on your Win7 ? … Help —> About Quicken
Any accounts you have in Quicken should just mimic your real world finances. It's not a parking space concept, with only so many - and you re-use old accounts..
If you still have this exact same account, then just enable the online downloads. If you no longer actually use the account, then just do an Add Account and setup any new accounts you now have.