How to reset sony xperia

hi there.
not sure if this is your phone as you did not give model number.
but try this.
First method:

1. In order to switch off the phone hold down the Power button for a short while.
2. Afterwards go to Settings and then to Backup & Reset.
3. Then selec Factory Data Reset and tap Reset Phone.
4. Choose Erase Everything if you are sure you want to clear all your data.

More items...

SONY Xperia XA F3113 - How to Hard Reset my phone - HardReset.info

www.hardreset.info/devices/sony/sony-xperia-xa-f3113/
or this one.
Restarting andresetting your device Sony Xperia XA support Canada English
or this.
Restarting resetting and repairing Sony Xperia XA support English
or this.
SONY Xperia XA F3113 How to Hard Reset my phone HardReset info

Please visit the below link and follow the steps to hard reset Xperia M2:
http://www.hardreset.info/devices/sony/sony-xperia-m2-dual-d2302/

GuruAid.com

restore settings

or this one note all data will be deleted

How to Soft Reset or Reboot or Restart SONY XPERIA T LT30p ?
To soft reset SONY XPERIA T LT30p, press the POWER BUTTON KEY for several seconds, we will see the menu to restart or turn off. Choose restart/reboot than the SONY XPERIA T LT30p will do the soft reset or restart. This is safe to do because non of important data or applications will wipe or erase.
#Option 1, Hard Reset SONY XPERIA T LT30p with Software Menu :

1. Make sure the battery is charge properly
2. Turn on SONY XPERIA T LT30p smartphone
3. Don't forget to backup all important data
4. Go to menu: Setting > Backup & reset > Factory Data Reset > Erase internal storage > Reset Phone
5. Choose Erase everything to continue and confirm you ready to do the format SONY XPERIA T LT30p
6. The SONY XPERIA T LT30p will continue the step until ready to use in clean factory default.

#Option 2, Hard Reset SONY XPERIA T LT30p with Flashtool applications:

1. Flashtool in the applications from Sony can be download from Sony website.
2. Flashtool software need to installed in you computer and ready with USB data cable
3. Make sure SONY XPERIA T LT30p battery is charge properly or full charge
4. Power off SONY XPERIA T LT30p
5. Boot SONY XPERIA T LT30p to flashmode with using: Volume Down Button and connect to USB cable at No.1 above
6. Follow the menu at you computer display, it is easy to understand the steps.

#Option 3, Hard Reset SONY XPERIA T LT30p with Hardware Key Button:

1. Make sure the battery fully charge
2. Do not forget to backup all important data
3. Turn off the SONY XPERIA T LT30p
4. Press and Hold together: Power Button + Volume Up Button for several seconds
5. Follow the menu at LCD screen to continue the hard reset SONY XPERIA T LT30p

You can choose the step options above to do hard reset while the SONY XPERIA T LT30p get problem or not running well. But we always suggest to do routine backup before your smartphone get problem. If SONY XPERIA T LT30p already stuck or run slowly or not responsive, then better try to do backup as you can because all important applications will be wipe or removed from SONY XPERIA T LT30p after doing master reset, but some data which saved at memory card will be safe, better to remove the microsd memory card before doing the hard reset.

http://www.hard-reset.org/factory-default/how-to-easily-master-format-sony-xperia-m-c1904c1905-c2004c2005-dual-with-safety-hard-reset/
Hope this helps.
You installed anti virus?

solution 1, Hard Reset SONY XPERIA S LT26i with Software Menu :

1. Make sure the battery is charge properly
2. Turn on SONY XPERIA S smartphone
3. Don't forget to backup all important data
4. Go to menu: Setting > Backup & Reset > Factory Data Reset > Reset Phone
5. Choose Erase everything to continue and confirm you ready to do the format SONY XPERIA S
6. The SONY XPERIA S will continue the step until ready to use in clean factory default.

solution 2, Hard Reset SONY XPERIA S LT26i with Flashtool applications:

1. Flashtool in the applications from Sony can be download from Sony website.
2. Flashtool software need to installed in you computer and ready with USB data cable
3. Make sure SONY XPERIA S battery is charge properly or full charge
4. Power off SONY XPERIA S
5. Boot SONY XPERIA S to flashmode with using: Volume Down Button and connect to USB cable at No.1 above
6. Follow the menu at you computer display, it is easy to understand the steps.

solution 3, Hard Reset SONY XPERIA S LT26i with Hardware Key Button:

1. Make sure the battery fully charge
2. Do not forget to backup all important data
3. Turn off the SONY XPERIA S
4. Press and Hold together: Power Button + Volume Up Button for several seconds
5. Follow the menu at LCD screen to continue the hard reset SONY XPERIA S

Be careful before doing this step to master reset, because all important data and applications will be removed from SONY XPERIA S, we always suggest you backup all important data before performing the hard reset.

Option : Hard Reset SONY XPERIA MIRO (ST23i/ST23a) with Hardware Key Button:

1. Make sure the battery charge properly before doing this step
2. Do not forget to backup all important data
3. Turn off the SONY XPERIA MIRO (ST23i/ST23a)
4. Press and Hold together: Power Button + Volume Up Button for several seconds
5. Follow the menu at LCD screen to continue the hard reset SONY XPERIA MIRO (ST23i/ST23a)

SONY ERICSSON Neo MT11i how to hard reset my phone HardReset info try this link

take out the battery and hold your power button for a while.. this s memory reset... then put the battery and power on... it will on.. then factory reset... problem solved