If replacing the Hard drive and/or performing a clean Windows Install are not options that are available to you, a factory reset will be the next best thing.
However the pre-installed software provided with many systems is, IMO, garbage. I have a Toshiba Satellite L300 which is significantly older and less powerful than the system you have been given which I purchased new. The Windows Vista install it came with was completely unusable, and since it was Home Premium and I had an Ultimate License, I performed a clean install. The difference was collossal. Currently I have it running Windows 8.1 without issue and if I had to I could use it for my everyday computing tasks, whereas with the preinstalled software, it was practically unusable even for basic browsing.