Selective Sync (Dropbox)
When the size of free disk space on you PC is not big enough, try Selective Sync on Dropbox.
Go to Dropbox > Choose gear icon > Setting
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Choose your account and selective sync
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Uncheck / Check folders you sync.
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If you uncheck the folder, the unchecked folder is deleted from your machine but the data still remains on Dropbox. If you need the former data, simply go to dropbox.com and search the stored data.
For more information, go to