The Dropbox directory which should be in jharvard directory is not there; in fact it is nowhere. Can anyone give me the exact link to the CS50 appliance download page?
Follow the instructions here to enable Dropbox
How to Enable Dropbox
This feature requires Internet access.
To make it easier to back up files within the appliance automatically as well as share them with your own computer(s), you can synchronize a directory in John Harvard’s account with Dropbox. If taking a course, just take care to respect the course’s policies on academic honesty.
Here’s how to configure the appliance for Dropbox.
Select Menu > Dropbox.
You should be prompted to "download the proprietary daemon" (i.e., software); click OK. The software should proceed to download and unpack.
You should then be prompted to set up Dropbox.
a. If you don’t already have a Dropbox account, leave I don’t have a Dropbox account checked, then click Next. Create your Dropbox as prompted.
b. If you already have an Dropbox account, check I already have a Dropbox account, then click OK. Log in as prompted.
If prompted to upgrade your Dropbox, simply leave 2 GB checked (which is free) then click Next, unless you want to upgrade to a paid account.
If prompted to Choose setup type, leave Typical checked, then click Install. If prompted to "merge", click Merge.
If prompted to take a 5-step tour, click Skip Tour; its screenshots won’t match what you’ll see in the appliance.
When informed That’s it!, uncheck Open my Dropbox folder now, then click Finish. A Dropbox icon should then appear in the appliance’s bottom-right corner.
Only those files and folders that you save in ~/Dropbox/ will be synchronized with your Dropbox account.