how I can set Stock ROM for SYMPHONY W85 (MTK 5672) device
http://www.4shared.com/office/9qBpEhd8/Symphony_W85_MT6572_Android_sc.html#

First you needs "ROOT" your device.

After that you needs a application "Link2SD". (If you need you can download it from play store).

Then start your processing.....
1. Open "Link2SD"
2. Open your desired/troubled application(Gmail/Maps/Blogger etc)
3. Press "Action"
4. Press "Convert to system app"
5. Press "OK" on dialog box
6. Please wait and then shows 'operation completed successfully'
7. After that restart/reboot your Android device

if you need a tools for ROOT your device, then you can use it.

ROOT TOOL