There is a known issue when upgrading your Asha 205 with software v4.51 whilst having a memory card in the phone.
The recommended steps are:
- Move your personal data to the memory card such as your pictures to free up the available phone memory. You will need at least 6MB of free memory on the phone before downloading and installing the updates.
- Remove memory card from phone.
- Perform the software update. For more information on Software Updates for Nokia Asha, please refer to http://www.nokia.com/global/support/software-update/asha-software-update
- After the update is completed you may reinsert the memory card and use the phone as normal.