- Do a clean installation of Windows 7 on your laptop. Which means that you'll end up with only Windows, no programs installed and missing a few drivers that you'll have to find and install (but this is easy, I can help you with that);
- Do a Factory Reset on your laptop, which will reinstall the OS that came with it as well as reinstalling the OEM bloatware. Once done, you would have to uninstall the OEM bloatware you don't need, one by one;
Sounds like a good plan to me, either one!
Though if it were me, would choose #1 over #2, because drivers are available & a clean install will perform better over the 2nd option, which in the end may require more work.
Also, any other software that would still be used today, such as Adobe Reader & Flash, needs a full removal & reinstalled freshly. And direct from the source, not 3rd party hosting sites, being sure to uncheck options for McAfee scans or Google software (Adobe must be desperate for cash to be bundling these). Due to so much adware being bundled into software, we cannot recommend even 'the best' 3rd party hosts. With Windows 7 or above, there is no need to install software for optical media burning, it's built into the OS, so that's one you can avoid.
It's like Aura has stated above, unless there are hardware issues that we are unaware of, the computer would run a lot better with any useless junkware installed. With that age of a computer, less software is more, I have one that's a bit older, and discovered the same thing recently. Most all of the Dell software from the reinstall set is considered to be garbage today, as a longtime registered Dell customer, they were kind enough to send me a Vista reinstall DVD w/out the bundled software, along with an updated driver CD (Optiplex 740), though I ended up using a Windows 7 Home Premium OEM DVD & COA that I purchased at Newegg on promo sometime back, and reusing my Windows Anytime Upgrade from Home Premium to Ultimate COA (this is permitted) from a dead PC for a huge upgrade.
Being that it has a physical TPM (Trusted Platform Module), this made Ultimate the right choice, to have an encrypted OS. Unfortunately, less systems ships with this option today than in the past, making BitLocker buggy on some systems. With a TPM, one is more secured & BitLocker works best.
So that was my situation also, and was able to install many of the Vista 64 bit drivers in Compatibility Mode that were required for the computer to properly run.
As long as your copy of Windows 7 is legit & the rest of your hardware is sound, you can download a Windows 7 SP1 ISO of the same type that you have & activate with your COA, though that may not be the one printed on the bottom of the notebook. Use the one shown by Speccy, Belarc Advisor, or RW-Everything (this fishes the Windows key out of the BIOS chip, but may be the same as that of Speccy or Belarc Advisor), if the one on the COA isn't accepted. Be sure to have or create Recovery Media set for 'just in case' a clean install won't work.
This doesn't cover everything, but is a start. Though I will advise that this is a lot of work, since you've stated in Post #3 that you're up to the task, just letting you know the way it is. You very well may get some satisfaction & lots of learning experience from this project, at a cost of time & effort.
We're here for you, should you need us!