No internet on my sont ericcson k8001

Sorry to say but for phone data, once its gone its gone. Theres no way to reverse it back. Its not like computer. The phone is using chipset memory data. Once u wipe it off by resetting it, the old ones will be gone.

Depends where it was flashed. Take it back to the shop or if you did it yourself repeat the procedure but first take out the SIM and battery and then replace after a few minutes just in case. Also try another SIM by the same operator if the phone is locked if not any operator.
If no success, You can use Wotan website to reflash. You need to buy credits and data cable that came with the phone
http://www.wotanserver.com/en/supported-phones/sonyericsson-w910-debranding/

You need to get GPRS setting from your operator for surfing web. Pls contact your operator.

the phone needs to be reflash to correct this issue this can be done online at a paysite called topsony.com or you can take it to a mobile store near you to have it flash there.

perform a software reflash from sony erricson's website or take it to the store to get the same done....
you will loose all your data so please back up the same

You need to reprogram your phone.

yes

take the phone and have the firmware either upgrades or reflash on the phone.

Brother it seems your phone's software problem. Such problem can be occured due to removal of battery in it's active mode or use the phone in less charged battery. Solution is to reflash it with new files...Any good technician with understandign of sony-erric's CID security and nice tools like Universal Box, SE TOOL can do this for you but he will charge you for that. It is not possible to do anything without tools, tools and rather costly.

okay well you need to reflash the software or replaced the flex cable on the phones.