Please help me! New to iPhone modding and have tried everything.

[WarrenV3214]

I have an iPhone 3GS running 4.2.1

I have tried everything to jailbreak my iDevice to no avail. I tried redsand, greenpoison, and neither works. Tried turning off my firewall, using a different machine, different OS, different cable, restoring my iPhone. What am I doing wrong? Any help would be appreciated.

[iYeow]

GP 6.1 should jailbreak your 4.2.1

[WarrenV3214]

It should but it doesn't. I dl gp and then put my iDevice in DFU mode and run gp and it never see's it. It never begins to jailbreak.