I have Kingston DTi /4GB data traveler pen drive but it shows by computer it didn't open open error how to remove this problem?

Pen drives behave very strange...some say they are like a betrayed friend...when u need the most they fail....
i still believe in 9 GB DVD...they are more dependable as they cannot be infected by any virus....and can be used for a longer time...also costs a few $$ than the most pen drives...
else u can use a re-writable 4.7 GB DVDs....a box of 10 DVDRW disk costs 2 $....a 8 GB pen drive costs $ 20 aprox