I believe what you are trying to do has already been done for Windows but NOT Linux, Android nor iOS.
As with any software there are system requirements.  Therefore Windows 7 will not run on a 486 dinosaur.
Another factor is the media on which the OS is installed.  The OS running from a USB flash drive runs much slower than it would from an internal HD. The OS on a SSD drive runs quicker than on standard SATA or IDE drives.
Amount and availability of RAM also affects the speed of the OS.  Here you have physical and virtual memory.  The RAM itself comes in different speeds affecting data transfer rate.  So an OS on a system with DDR 2100 will run a little slower than the same system with DDR 400.
A 32 bit OS cannot use more than 3.5 GB of physical RAM.
Excluding differences in hardware, there are some software tweaks to enhance the performance of the OS.
Windows allows the user to adjust several settings that enhance performance. One such tweak involves defining a block of virtual memory. Some older systems will NOT allow more than 4096 or 4094 MB of virtual memory on each partition of the HD.  Remember virtual memory allocates space on the HD for the paging file.
A 32 bit OS can have an unlimited amount of Virtual memory.  The limit is defined by the available capacity of the HD. I like to define a paging file of 8192 MB on C:\ and D:\.  Some legacy systems will only allow max 4094 MB or 4096 MB paging file on C:\ and D:\ partitions.
Available RAM is also a factor.  Unnecessary programs and processes running at start-up will reduce the amount of available memory and tie-up the CPU.  This will slow down the operation of the OS. 
To provide maximum available RAM, I use a program called Winpatrol.  It controls what applications run at start-up. True you can use Ms config to prevent non Microsoft services and programs from running at start-up. But Winpatrol is also a HIPS (host intrusion protection system).
Process Explorer is another useful program to identify and stop processes that hog the CPU.
Another factor is file fragmentation.  Fragmentation occurs when files are deleted and copied.  A fragmented HD appears like Swiss cheese.  The holes represent the area on the HD that once contained a file that has been deleted.
Serious file fragmentation can cause boot failure. Typically an OS running on a fragmented HD will run slowly.  Sometimes the HD will be noisy because it trips up passing the holes while it seeks data sequentially.
Therefore another tweak involves making all files contiguous on all partitions of the HD.  I use Diskeeper pro to manually de-frag all partitions of the HD. I avoid using Diskeeper's automatic de-fragmentation because it may interfere with the smooth quick running of applications.
Nearing 100% usage of the hard disk will slow down the OS and Windows will complain prompting the user to erase temporary files.  When partitioning hard drives one must consider scalability by allowing extra room for the future installation of software.
Windows needs at least 20% free on all partitions!
Generally I use the following partioning scheme for the OS/data partition:
40GB HD: 19/21;  60GB HD: 19/39;  80 - 120 GB HD: 37/remainder;  160 GB HD: 52/100;  200 - 750 GB HD: 74/remainder;  1+TB HD: 100/remainder.
For creating space on a HD that is fully used, I use sequioia view to locate large files and folders that can safely be deleted.  Sequioia view is also useful to locate customer's data that needs to be moved to my HD before I can deploy my images of Windows onto the customer's HD.
Perhaps the biggest factor slowing down the OS is malware from the Internet. Much of this malware exists in the temporary Internet files and browsing history and cookies created automatically when you surf the Internet. I use iL System wiper to automatically erase browsing and other history, cookies and temporary files every time the user shuts down, logs off or restarts the OS.
Another malware fighter is spywareblaster.  This free software helps protect the browser from malware.
Essential is a good firewall.  I use Psygate firewall on my images of Windows XP and I use PC Tools firewall on my images of Vista and Windows 7.
Firewalls help prevent attacks from hackers. However, they often block FTP.
Another important Internet security procedure is to setup a password to access the router.
Viruses attacking the BIOS can be thwarted by creating a BIOS password.
Of paramount importance is an Antivirus software that never expires. All my images of Windows contain the best virus protection available, Avast Antivirus with the 30-years license key, W6754380R9978A0910-4TZ59467
Other security considerations include disabling system restore.  Whenever system changes are made, the OS stores a backup of the system the way it was before the change.  System restore points can consume a lot of HD capacity.
When removing malware it is important to first disable system restore. Malware can use system restore to reincarnate themselves.
All my images of Windows have system restore disabled.  Should the OS need to be restored then my customers can rescue their Windows by restoring an image of C:\.  To image C:\, I use Bootit NG.
This rescue procedure does NOT erase my customer's data because the data folders for each user account resides on a separate data partition. However, partition, C:\, containing Windows and programs is wiped by the rescue procedure and is reset to its original state.
Another unconventional security tweak is to disable automatic Windows update. IMHO these Windows updates destabilize the OS and if your Windows is NOT specifically licensed for your computer then the update will make Windows NOT genuine and your OS will be populated with nag screens and become unusable after 30 days!
Remember I am deploying images that were created on my computer. My Windows are the real deal RTM versions that have been cracked.  As a rule cracked software must never be updated or registered.
Hope this helps!