Unable to map network drive(s)

Co-worker trying to solve this:

Writes: "I have an end user in IL, he can get email, print and use citrix apps, but cannot map a network drive, I logged on as myself and I cannot map a network drive. The computer account has been checked, was told everything was fine on that end, I have worked with NetOps, they said all network equip is fine, checked all firewall settings, I have disabled all the ones I can. "

Suggestions?

Thx.