I bought 4 gb of ram for my MacBook Pro version 4,1. I bought 4GB of 667MHz of Kinsington. The ebay vendor that I had purchased it from has said to flash the bios. Have you ever had to do this? I have never done this before but am kinda leery in trying. I'm not sure what the bios does as the last time I ran into this was over 15 years ago when I owned a 286 PC. I am not new to computers. I have upgraded the hard drive on this computer which is not user recommended by apple. Below I've copied the vendors instructions. In your opinion what would be the best thing to do. Thank you, I appreciate your help. Below are the emails. Hello, The memory is compatible. Please try flashing the BIOS (clearing the CMOS). If the does not work please return the memory. Please copy and paste this message into your future messages to us so we have it for our reference. Thank you, Customer Service S2 Sent: Wednesday, May 27, 2009 8:39 PM Subject: Re: You've received an answer to your question about item KINGSTON 4GB DDR2 PC2 5300 667 MHZ 2X 2 GB SODIMM 4GB G I'm okay with the free tech support for now as I would like this to work with the ram I recieved. Below is my MacBook Pro's information. Thanks. On 27-May-09, at 11:35 AM, eBay Member: fastflashstore wrote: Your registered name is included to show this message originated from eBay. Learn more. Seller has responded to your question about this item Do not respond to the sender if this message requests that you complete the transaction outside of eBay. This type of offer is against eBay policy, may be fraudulent, and is not covered by buyer protection programs. Learn More. Hello, We are sorry to hear that you are having problems with your order. (merchandise not physically damaged) Item was tested and working upon shipment. We can offer you free tech support (please keep in mind that this is a 2- way exchange of emails...please be prepared for this to take time.). We offer this so that if there is a possibility of resolving your problem before asking you to return the item, we would like to be able to do this for you. There are a number of reasons why products don't work including density issue (high vs low density), Cas Latency, BIOS, SDHC vs SD, UDMA vs DMA , etc. If you wish to seek tech support - please reply back with the make and model of your hardware (Computer - motherboard) Mobile device/ Camera/etc. Please note that even though you might have a lot of knowledge about the item - there is always a possibility that there is something we can share with you which might help you resolve the problem before sending it back. In any case, if you wish to just send it back - here are the details: We have sent an RMA form to firstname.lastname@example.org to return with your order. Instructions and return address is in the RMA form.. Once your return is received, it will be processed and given to our returns department. They will then email you with your options or the action that is being taken. If you have any questions concerning your return, please email our returns department directly at email@example.com and put RMA RETURNS in the subject line. Please copy and paste this message into your future messages to us so we have it for our reference. Thank you, Customer Service S4 - fastflashstore Did this answer your question? If not, let the seller know.