I have downloaded ptc creo 4.0 student version but the mail from your end specifies it as creo 3.0 also the product code entered is not working for license.
move all files from C:\ProgramData\PTC\Licensing directory to another directory, for example create C:\temp_license for this purpose ... you need to get empty C:\ProgramData\PTC\Licensing directory
install Creo
K-12 students can use Product code BE410708EDSTUDENTEDK12 ... license file must contain INCREMENT CREOPMA_SchoolSTD4 ptc_d 35.0 ...
University students can use Product code BK410705EDSTUDENTUNICL ... license file must contain INCREMENT CREOPMA_Student3 ptc_d 35.0 ...