Hello Duelz, and welcome to SevenForums.
First off, could you please update your system specs so we know what components you have. That will help us to give you recommendations.
Honestly though, Win 7 is pretty well optimized right out of the box. I've had to do very little for it to run well on most systems, including those with little memory or a slow processor.
What I would do is...
1 - Make sure the only programs that run on startup are ones you need. I use iTunes, but I don't have any of the iTunes or QuickTime start up programs running. Until I need to use those programs, there is no need for them to run. However, I make sure my sound card control panel and Logitech keyboard programs are running at startup since I use both of those as needed. Your the only one who make a decision on what need to run and what doesn't at startup.
2 - Defragment your hard disks (except for SSD drives). As programs and files get added and removed, gaps open up on the disk and then when new files/programs are added, they're added in the first open spots first. That causes fragmentation and that means it take more effort to find all the bits. Now, hard drives today are fast, but on slower systems with low memory or on older hard drives that could be an issue. I would defragment every couple of weeks or find a program that will do so when your system is idle.
SSD Drive are different. Think of an SSD drive as a huge thumbnail drive - all the memory is on chips. There is no need to defragment an SSD since its near instant access to any portion of the drive. However, the limitaiton is that if a portion of a sector is used the drive controller will not open up that sector to be reused until the entire sector is empty. If you have lots of smaller files, you may not see a sector reused that may result in uneven use of the memory chips and may wear them out. I would occasionally consolidate free space so that those sectors get used more often. That helps to keep the use of the chips somewhat even and slows down the eventual death of the flash memory.
3 - I would honestly not touch any of the services unless you absolutely need to. For instance, since I use IMO a better anti-virus/malware program than Defender, I disable its services so there is no conflict. I would not be concerned about losing memory or speed due to services. I would look more at possible conflicts like I mentioned above.
Hope these help....
T
