Hi everyone. I hope this is the correct place for this thread. If not my sincere apologies. In brief -Manufacturer: Dell -Machine: Dell Optiplex 755 -Motherboard Model: -Bios revision: A22 (full filename O755-A22.exe) -Bios Type: Dell Phoenix BIOS -Bios Download Link: h t t p : / / d o w nloads .dell .com/FOLDER01133147M/1/O755-A22.exe -RW Everything Report Download Link: h t t p s : / / www . mediafire . com / ?sws38tp821abyos Longer version I've spent most of today browsing this and other sites learning about how to customise a BIOS, and I'm a bit stuck now. I hope someone would be kind enough to help me. What I'm trying to do I'm a hardware engineer working for a small charity. We collect, process and reuse or recycle IT equipment from various places, and then supply this equipment at low cost to other charities and non-profits around London. At the moment we have about 300 Dell Optiplex 755s with Pentium Dual-Core E2160 CPUs. We are refurbishing them to run Windows 7 for our clients, but even with 6GB RAM they are still much slower than I would like. These CPUs handle overclocking very well, and the machine hardware is designed for faster, hotter CPUs. If the overclocking can be done, it shouldn't cause much trouble with heat or stability. The problem is that it is very difficult to overclock any Dell machine. I would like to make a customised BIOS which overclocks the CPU, and modifies other variables for the necessary stability. The machines are low value and we have a large number of them. If they can be successfully and stably overclocked, they will become vastly more useful and valuable for us and our clients. Since we have a large number of them, I can afford to brick a few attempting to do this, if it means that the rest can be significantly upgraded. What I've done so far I downloaded the latest BIOS update from Dell and applied it. Using Phoenix/Dell/EFI SLIC Mod v2.59 I've extracted the exe file and applied a SLIC file (had some trouble with the checksum but I think that was an older version of the program). So now I have a bunch of extracted files (the important ones I think are O755-A22.hdr and O755-A22_SLIC.hdr) which should be editable since the certificate has been applied. I think what I need to do is find the correct settings for overclocking in RW Everything, modify the AcpiTbls.rw file and apply it in the Phoenix Mod Tool. Where I'm confused 1. Does RW Everything actually allow you to create extra menus in BIOS that are editable? So I could create a custom BIOS with customisable overclocking options? Or does modifying a BIOS this way just apply a permanent change? The documentation on RW Everything seems a bit sparse, or it might just be over my head. 2. I still need to figure out what the overclocking settings should be. If RW Everything creates editable menus then I can just include the extra options and test from there. If it doesn't create editable menus then I will use software overclocking and stress-test the machines for several days to figure out what to use. 3. Can someone give me some guidance on what files/parts of the .rw file I need to edit once I have the appropriate settings? 4. Now that I've unpacked the exe, do I need to modify the .hdr file in Phoenix Mod, or has the actual exe file itself been modified, and should I continue to put that in the "Original BIOS" field. 5. If the exe file itself is not being modified, how do I repack the components back into an exe file when I eventually flash the BIOS? I think that's it at the moment, sorry if it's a bit long-winded, and thank you very much in advance for any help you can give me. This is something I've never looked at before in my life, and it's much more complex than I had anticipated. Assuming all goes well and I can make a custom BIOS with overclocking for these machines, I plan to make a How-To for our website that I'll also post here, with all the relevant custom files. There's loads of these machines around (in London at least) that are currently being discarded, so it would be cool to save a few more from landfill and keep them useful a while longer. Thanks again.