cursor jump

Hi, the "jumping cursor while typing" problem had plagued me for 4 months on my Dell XPS M1730 laptop. I tried just about every "FIX" to no avail. I even sent the laptop into Dell, they switched out some hardware, sent it back and it still had the problem... Then Dell sent a Tech out to my home, who changed out the touch pad, Keyboard and some other integrated circuit stuff and it still was problematic as before... Eureka; I found a FIX which took care of MY particular Problem; The problem I found is a "Boot Sector Virus" issue. I fixed it by starting my Computer in Safe Mode F8, then doing a Virus Scan. When You Virus Scan in Safe Mode, the Virus cannot Hide Itself from the Scanner. At least this one worked for Me. How I figured this out is when I reformatted my hard drive, then loaded Windows 7 and other software, the problem still existed; therefore I deduced, the only place for Virus information to hide was in the Master Boot Sector. After looking up this Pesky Virus problem online, I see almost 112,000 Posts relating to it! Good Luck!