V4VIRGILANTE

I have had this computer since 2012, so I was hoping to get a few more years out of it before changing computer. Basically, if the comp is knocked or lifted suddenly, it either blue screens, or switches off entirely. When it comes back on, I get a screen that says it's checking the disc, and undergoes a check for "bad" or "orphan" files, amongst other things that are a bit beyond my level of PC literacy. Previously, the laptop had been quite slow, for example, the keyboard would be slow to respond to my typing, which would result in sentences being very garbled. The battery also doesn't last as it used to. I think the inside is probably very dusty (I was living in a very old house for a bit.) For a bit, I also heard a scraping sound coming from the inside, which I think may have been the fan. If you have any advice, please let me know. I'm a PhD student, so I really need my computer to survive this. Many thanks in advance!