If the above steps didn't help, please refer to
this:
http://social.msdn.microsoft.com/Forums/en-US/netfxsetup/thread/f56cc6e4-c2bf-490c-b87b-3e22b1e6b935
http://stackoverflow.com/questions/523879/need-help-getting-ngen-back-into-working-condition
Else I recommend you post your issue here:
http://social.msdn.microsoft.com/Forums/en/category/netdevelopment
*Trust me you will get better help there, I can tell my contacts on that forum to come over to your post and post any useful resolution. But for that to happen you need to wait until Monday.
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