An old model Lenovo Laptop?

Model 2048-23Q & sl. no. MA8HKY8 is an old model laptop. Since purchase, it has been noticed that whenever drafting process in MS Word 2003 (OS is Windows XP ), sometimes, cursor is not forward character by character. Sometimes, it jumps from one cursor position to another position, may it above a paragraph or some other position elsewhere. It is truly hard to write in full concentration without seeing the screen. Is there any solution? Please provide in details. Touch pad already changed, use very careful fingering on keyboard, so, no manual touch on the touch pad, the user, using MOUSE for any further cursor movement. Then? It seems helpless, as no response is getting from lenovo customer care unit or website. They inform, the model is obsolete. Now what to do to solve this irresistible issue.