I'm pleased to say my windows 7 installation did the trick.
I ran repair mode in sony pc companion.
Thanks for your suggestion, very helpful.
Now i'm having problem rooting on flashtool.
it gets stuck on 'Running installftkit as root thru sysrun'
seee.. I told u..!! ths is y I said its easy.. watever hell ur phone goes into, sony pc companion wil repair nd make it fully stock.. then u can start all over again.. use flashtool 09.11 nd just rooting nd unlocking bootloader is just a click away.. its just 1 click..! wat cud possibly go wrong. check rooting forums.