Problems with uploading to board

I wanted to make a disdrometer that i can read on my PC but at a very convenient time my arduino refused to program. I thought at first that it might be because i changed the polling rate of my USB mouse but i rolled back to the original usbsys file to no avail. I received this error message:

avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

Thanks in advance

When that happens to me it's usually because I have the wrong board type selected and therefore it's trying to use the wrong baud rate for the bootloader. I have several 168 processors but one has the original Diecimila bootloader and the others have the optiboot bootloader like the UNO. They use different baud rates and that catches me on occasion.

i double checked that i have the correct options selected (board, com port) but no avail. I'll try to boot into safemode later and fix the polling rate and hope it works. Any suggestions in case it wont work?

Be aware that the 'board' setting isn't really the board, its the chip+bootloader setting - so for instance I regularly use 'Duemilanove' setting on my Uno because I've several older 328 chips with the older bootloader that I use with it - similarly a newer bootloader chip on an older board needs the 'Uno' setting to work - so its worth trying both settings in case you've lost track of which chip has which bootloader - particularly if you buy a 328 with bootloader (older stock will have old bootloader)

I tried using the board settings that use the arduino328 to no avail. I really think it's my PC, i'll try uploading a sketch from a different PC.