I'm sure this will be an easy question: What would be a good replacement CPU Fan/Heatsink for a Intel Core 2 Duo E8500 processor? We used the one supplied with the E8500 when we built her computer and it is making a high pitched noise now. Can I just replace the fan?
Choose from Cooler Master, Thermalright, Prolimatech's lineups. Just remember to consider size and performance.
Size because it has to fit into the case, so look for "case clearance" required or you can calculate if it will fit with the side panel opened using the "heatsink height".
As for performance just read a few reviews about the specific models you're interested.
The Core2Duo E8500 was a socket LGA 775 CPU so just remember this when choosing the cooler models, as it has to have support for this socket ofc.
As for specific models recommendations, right now, i'd suggest the Thermalright True Spirit for Intel or the already venerable Cooler Master Hyper 212 Plus.
Another thing to consider when choosing a cooler is motherboard heatsinks (some have extra high ones that could interfere with the cooler's heatsink) and slot clearance (some mobos have the first PCI-E x16 slot closer than usual to the CPU socket, making impposible to mount the cooler in a vertical orientation).
Oh there is also RAM heatspreader clearance to be considered, some coolers have a certain RAM clearance since the fin array go over the first ram slot even when it mounted in a vertical orientation.
I could go on but i think you have enough info to find yourself the best cooler for your budget.