Can i claim expenses for the whole year if I was a contractor for only 2 months. (i have a 1099 and a w2 from the same company)?

Not quite, you would be self-employed as a subcontractor and report your business expenses on a Schedule C for two months.

After being hired on and getting a W-2 wage, you can no longer take the expense as a business expense, but now it would be treated as an employee unreimbursed expense.  This would now be reported on a Schedule A itemized deduction, limited to the amounts above 2% of your AGI.  The standard mileage rate for 2017 is $0.535.

I have the same issue. I've been a contractor for 2 months, signed a W9 and then signed a W4 when I got hired as a regular employee for the same company. I would like to know how did you pay your quarterly taxes for working 2 months as a contractor?