This depends on the phone used. The latest Nokia phones are able to keep personal data in place - but there is an issue with older phones. It is highly recommended to take a backup before the firmware update.

If the applications were downloaded from Nokia Store you can easily redownload them by signing into Nokia Store website and accessing My Stuff.

This topic is valid for:

Nokia,Nokia C6,Nokia C6,Nokia C5,Nokia C3,Nokia C2,Nokia E73,Nokia E72,Nokia E71,Nokia E71x,Nokia E7,Nokia E63,Nokia E6,Nokia E5,Nokia N97,Nokia N97,Nokia N95,Nokia N95 8GB,Nokia N8,Nokia X6-00,Nokia X3,Nokia X2-01,Nokia 808 PureView,Nokia 700,Nokia 6790,Nokia 6350,Nokia 5800,Nokia 5310,Nokia 5230,Nokia 5130,Nokia 2720,Nokia 2330