Virus? No access to the flash drive

start — run — cmd
g:
attrib (to see if a file with the attributes SHR or SH)
attrib-r-h -s /s /d
del imaginasia
del autorunf.inf
del desktop.ini
rmdir RECYCLER /S /Q
echo NOPASARAN > autorun.inf
echo NOPASARAN > recycler
attrib +h +s +r autorun.inf
attrib +h +s +r recycler

On screen not enabled viewing hidden files.
99% of what's in the root is a file autorun.inf.
Turn on show hidden files or view flash FAR TotalCommander'ω or ω and delete autorun.inf
And after that, check your computer by antivirus with fresh bases.

Can access flash-closed security policies?

was a virus, povredili autoloader, reformat the flash drive and everything goes

Look in the registry:
HKEY_CURRENT_USER\\Software\\Policies\\Microsoft\\Windows\\DeviceInstall\\Restrictions parameter DenyRemovableDevices
HKEY_LOCAL_MACHINE\\SOFTWARE\\Policies\\Microsoft\\Windows\\DeviceInstall\\Restrictions parameter DenyRemovableDevices
HKEY_CURRENT_USER\\Software\\Policies\\Microsoft\\Windows\\RemovableStorageDevices parameter Deny_All
HKEY_LOCAL_MACHINE\\SOFTWARE\\Policies\\Microsoft\\Windows\\RemovableStorageDevices parameter Deny_All

Through the address bar, enter, then Windows does not interfere.