HELP PLEASE!!!

Hi guys, I hope you can help. Just installed the 744F and now my framerates are between 7-9!! Did a search on the forum and tried editing out the standby gauge + changing framerates down to 5 on the pmdg slider (i think the last one slightly helped) i uninstalled the freighter and pax version started again and it's still messed up! Degrag checked for trojans, it's only afer i installed the-400F She was running perfectly before and i even put all the sliders to the left but still max frames were 10!! If i change to any other aircraft its back to 25-30fps everything full right except clouds at flytampa seattle.System Pentium 4 3ghz 1.5gig ddr ram 120gig seagate hardrive gforce 6800 512mb I have been a very happy customer of yours with well over a hundred hours on the 747 with this exact rig, pls help. Robert Prest BTW my father fly's the 747-400 for an asian carrier and is very impressed with your software