arks172

Try updating your java, and if it doesnt work, use tekkit launcher .jar not .exe

I've had the problem too. I didnt want to mess around, with it, propably because i am lazy, so i just deleted techniclauncher files in appdata. If you are going to do it, i suggest you back up your world onto your desktop (i didnt becaise i play tekkit SMP and dont have SSP world

Ive had that before. I had it with the same antivirus as you. I fixed it by uninstalling avg and installing avast. I could have tried adding it to exeptions, but i am not very picky about my antivirus so i just went for avast.