To the two of you - welcome to BC !
Comraycom's analysis may be overly pessimistic, but you are dealing with a laptop that must be at least five years old so his third proposal, while harsh, makes a lot of sense. However, if you have been using this computer all this time, there will be a lot of data on it you would like / need to keep. All is not lost. If you do decide to buy a new laptop you will be able to salvage the data quite easily.
Remove the hard drive from the Dell 1535. This is normally quite easy to do, and if in doubt you will find videos on YouTube on how to take this computer to pieces. Just make sure you disconnect from the mains and remove the battery before you start. Then beg, borrow, steal or even buy a 2.5 inch HD enclosure, put the HD in this, and connect to your next laptop normally by USB. You will then be able to read the old HD and copy data you want off it to your new one.
Of course, if you have a recent back-up, then you won't need to go to this length. Hardware can be replaced, operating systems and applications can be re-installed - the really valuable stuff on any computer is your own work.