I am facing problem regarding to Virtualization installation pertion selection problem . The same OS i have installed on another PC without any problem during guest os installation .
I am trying to install guest Fedora8 or RHEL on parent Fedora 8 OS . Pc is Intel - p4 - Dual core .
While setting up guest os , I m getting Para / full virtualization option . In any case , when I m getting guest os installation pertion section or a image file which will hold my guest os installation ; Forward button is unable to process to the next step .

I had tried with so many things.........................
I choose one ext3 formatted partition on parent Fedora8 os .But not done .
I choose only fdisk created partition , not formatted . But not done .
I mounted another ext3 partition and trying to install guest os in one file into that mounted partition . But not done .

Ok...again, I'll suggest you UPGRADE YOUR OS. Fedora 8 is VERY OLD...the latest is FC11, and 12 will be released very shortly, if not already. If you're having problems in getting things to work on even fairly modern hardware, the fact your OS is so old, may have alot to do with it.

Thanks TB0ne , for your reply . Ok I will try on updated fedora version as you suggested me .
Is there same kind of problem relating to RHEL5 ; if so could you please suggest me , what would be the way . Because if I m not wrong , virtualization was introduced first on RHEL5 platform , among other RHEL products .

No, you're wrong. Virtualization was introduced well before RHEL5. If you're not going to pay for support, don't use RHEL, but use CentOS instead.