Few days back iPhone Dev team had released Redsn0w 0.9.6 B1 to Jailbreak iOS 4.1 on iPhone 3G & iPod Touch 2G and it also supports iOS 4.2 Jailbreak. However Redsn0w 0.9.6 B1 is only available for Mac OS X users and for Windows it is still under testing.
Well no need to disappoint Windows users as iH8sn0w has released updated version of Sn0wbreeze, Sn0wbreeze 2.0 for Windows to jailbreak iOS 4.1 on iPhone 3GS, 3G & iPod Touch 2G, 1G. Sn0wbreeze 2.0.1 uses custom firmware method to jailbreak iOS 4.1 hence you can preserve baseband and unlock it with Ultrasn0w if it is on supported baseband.
Sn0wbreze 2.0 to Jailbreak iOS 4.1 on Windows
Update: iH8sn0w has released update to Sn0wbreeze 2.0, Sn0wbreeze 2.0.1 to fix the Error 34 which users encountered while restoring firmware via iTunes created with Sn0wbreeeze 2.0.
The complete step by step guide to jailbreak iPhone 3GS iOS 4.1 with Sn0wbreeze 2.0.1 will be posted here soon, so stay stunned with us for more jailbreaking news.