  We report on detailed Monte Carlo inversion analysis of five OVI systems from
the spectrum of the bright quasar HE 0515-4414 (z_e = 1.71). The associated
system at z_a = 1.697 with the neutral hydrogen column density N(HI)= 4.4
10^{13} cm^{-2} shows pronounced absorption from highly ionized transitions of
CIII, CIV, NV, OVI, SiIV, and probably SVI. We found that only a power law type
ionizing spectrum (J_nu propto nu^{-1.5}) is consistent with the observed
sample of the line profiles, i.e. the system is definitely intrinsic. The
relative metal abundances give almost the solar pattern and the metallicity of
about 5 times solar. The system originates in a thin shell of the line-of-sight
thickness L <= 16 pc. Two OVI systems at z_a = 1.674 ([C/H] = -1.6) and 1.602
([O/H] = -1.1), arising in intervening halos, have linear sizes of L = 3-14 kpc
and 17 kpc, respectively. Absorption systems at z_a = 1.385 ([C/H] = -0.3, L =
1.7-2.5 kpc) and z_a = 1.667 ([C/H] = -0.5, L = 1 kpc) exhibit characteristics
very similar to that observed in metal-enriched high velocity clouds in the
Milky Way.These systems are probably embedded in extremely metal-poor halos
with [C/H] < -2.4 (z_a = 1.667) and [C/H] < -3.7 (z_a = 1.385). We also found
two additional extremely metal-poor Ly-alpha systems at z_a = 1.500 and 1.681
with, respectively, N(HI) = 1.7 10^{15} and 1.8 10^{15} cm^{-2} and [C/H] <
-4.0 and <-3.0, - an indication that the distribution of metals in the
metagalactic medium is utterly patchy. Our results show that the ionization
states in the analyzed OVI absorbers, ranging from z = 1.4 to 1.7, can be
maintained by photoionization only and that the fraction of the shock-heated
hot gas with temperature T > 10^5 K is negligible in these systems.
