Ahh I see, should be no issue to use but as richiestang_78 has said, just some rubbing alcohol or some cleaning fluid with a q-tip should take that of with no issues...TIM just means Thermal Interface Material...
It would be great to see a picture, though if the Thermal paste is not on any circuits it should be more than fine. Also if you have non conductive Thermal paste it should be okay to leave...What TIM are you using?
Ahh I see, should be no issue to use but as richiestang_78 has said, just some rubbing alcohol or some cleaning fluid with a q-tip should take that of with no issues...TIM just means Thermal Interface Material...