Re: Will it be possible to replace my current CPU fan with a compatible, albeit updated, fan? you did not say which inspiron  desktop model you have?  If I guess one possibel old inspiron could be 530 (LGA775 socket) or 620 (LGA1155 socket).  you can update the cpu fan to a newer model inspiron cpu fan.  but before you do that, consider what makes your current fan loud. if system is still working, then it could be you have poor thermal contact btn heatsink and cpu.  try repasting cpu after cleaning old paste.  also check for chassis internal dust rabbit blocking air flow. if system does not POST (which did not sound like it, since you want to optimize but not rescue a PC), then loud fan can be caused no POST issue separate from the fan.
I have been trying to call the 800-number for out-of-warranty service calls but so far, it is not responding ("technical difficulties").  Perhaps someone at the forum can help steer me in the right direction.  The question I wish to post is a simple one:  Will it be possible to replace my current CPU fan with a compatible, albeit updated, fan?  I have learned that Dell computers do not accept third-party components or hardware, so that greatly limits the field in which I must conduct my search for a Dell fan that is compatible with a model this old.  I am willing to consider the fee that the out-of-warranty service techies require to respond to my inquiry, as long as it's within my tightly managed budget. But so far, it looks like that service is out to pasture. Sheesh.  What does it take to get my computer back to near-perfect operation again? CartoonMan, longtime Dell User
"Revving" CPU fan