This allows you to play the game with modified files.
CREDITS:aru
Install GTA IV PC patch first.
Run from drive were gta iv is installed.
Hit backup & patch button. mod your sh*t and have fun.
Hit restore to restore orig files.

Backed up files
38.2MB
commondataaction_table.csv.bkup
commondataaction_table.xls.bkup
commondataaction_table_backup.csv.bkup
commondataambient.dat.bkup
commondataanimgrp.dat.bkup
commondataanimviewer.dat.bkup
commondataanimviewer_images.txt.bkup
commondataar_stats.dat.bkup
commondatacarcols.dat.bkup
commondatacargrp.dat.bkup
commondatacarmods.dat.bkup
commondatacj_gta.dat.bkup
commondatacj_images.txt.bkup
commondataclothes.dat.bkup
commondatacredits.dat.bkup
commondatacredits_360.dat.bkup
commondatacredits_ps3.dat.bkup
commondatadefault.dat.bkup
commondatadefault.ide.bkup
commondatafemaleplayersettings.dat.bkup
commondatafonts.dat.bkup
commondatafrontend.dat.bkup
commondatafrontend_360.dat.bkup
commondatafrontend_menus.xml.bkup
commondatafrontend_pc.dat.bkup
commondatafrontend_ps3.dat.bkup
commondatafurnitur.dat.bkup
commondatagta.dat.bkup
commondatagtarainemitter.xml.bkup
commondatagtarainrender.xml.bkup
commondatagtastormemitter.xml.bkup
commondatagtastormrender.xml.bkup
commondatagtxd.ide.bkup
commondatahandling.dat.bkup
commondatahud.dat.bkup
commondatahudcolor.dat.bkup
commondataimages.txt.bkup
commondatainfo.zon.bkup
commondataintroloc.csv.bkup
commondataintrospline.csv.bkup
commondataleaderboards_data.xml.bkup
commondataloadingscreens_360.dat.bkup
commondataloadingscreens_ingame_360.dat.bkup
commondataloadingscreens_ingame_pc.dat.bkup
commondataloadingscreens_ingame_ps3.dat.bkup
commondataloadingscreens_pc.dat.bkup
commondataloadingscreens_ps3.dat.bkup
commondatamain.sc.bkup
commondatamaleplayersettings.dat.bkup
commondatamap.zon.bkup
commondatamelee.dat.bkup
commondatameleeanims.dat.bkup
commondatamoveblend.dat.bkup
commondata
av.dat.bkup
commondata
avprecalc.dat.bkup
commondata
etworktest.dat.bkup
commondata
umplate.dat.bkup
commondataobject.dat.bkup
commondataold_anim_action_table.xls.bkup
commondataped.dat.bkup
commondatapedgrp.dat.bkup
commondatapedpersonality.dat.bkup
commondatapedpopulation.dat.bkup
commondatapedprops.dat.bkup
commondatapeds.ide.bkup
commondatapedvariations.dat.bkup
commondataplants.dat.bkup
commondataplayersettingslights.dat.bkup
commondatapolydensity.dat.bkup
commondatapopcycle.dat.bkup
commondatapopcycle.datnew.bkup
commondataprecincts.dat.bkup
commondata
adiohud.dat.bkup
commondata
adiologo.dat.bkup
commondata
elationships.dat.bkup
commondatascenarios.dat.bkup
commondatascrollbars.dat.bkup
commondatashockingevents.dat.bkup
commondatashorelines.dat.bkup
commondatasonglist.csv.bkup
commondatastatdisp.dat.bkup
commondatastockshake.txt.bkup
commondata	askparams.txt.bkup
commondata	hrownweaponinfo.xml.bkup
commondata	raincamnodes.txt.bkup
commondata	xdcut.ide.bkup
commondatavehicleextras.dat.bkup
commondatavehicles.ide.bkup
commondatavehoff.csv.bkup
commondataversion.txt.bkup
commondatavisualsettings.dat.bkup
commondatavisualsettings.xls.bkup
commondatawater.dat.bkup
commondataweaponinfo.xml.bkup
commondataworldblanket.dat.bkup
commondatacdimagescarrec.img
commondatacdimages
avgen_script.img
commondatacdimagesscript.img.bkup
commondatacdimagesscript_network.img
commondatacontrolsdefault0.cfg.bkup
commondatacontrolsdefault1.cfg.bkup
commondatacontrolsdefault2.cfg.bkup
commondatadecisioncop.ped.bkup
commondatadecisionfireman.ped.bkup
commondatadecisiongangmbr.ped.bkup
commondatadecisiongp_justfollow.ped.bkup
commondatadecisiongp_norm.ped.bkup
commondatadecisionm_empty.ped.bkup
commondatadecisionm_norm.ped.bkup
commondatadecisionm_plyr.ped.bkup
commondatadecisionm_tough.ped.bkup
commondatadecisionm_weak.ped.bkup
commondatadecision
_norm.ped.bkup
commondatadecisioncombatcop_nrm.cmb.bkup
commondatadecisioncombatcop_wl1.cmb.bkup
commondatadecisioncombatcop_wl2.cmb.bkup
commondatadecisioncombatcop_wl3.cmb.bkup
commondatadecisioncombatcoward.cmb.bkup
commondatadecisioncombatempty.cmb.bkup
commondatadecisioncombatgp_cr.cmb.bkup
commondatadecisioncombatgp_hide.cmb.bkup
commondatadecisioncombatgp_no.cmb.bkup
commondatadecisioncombatgp_pr.cmb.bkup
commondatadecisioncombatm_boss.cmb.bkup
commondatadecisioncombatm_coward.cmb.bkup
commondatadecisioncombatm_cr_de.cmb.bkup
commondatadecisioncombatm_cr_fi.cmb.bkup
commondatadecisioncombatm_cr_no.cmb.bkup
commondatadecisioncombatm_empty.cmb.bkup
commondatadecisioncombatm_hide.cmb.bkup
commondatadecisioncombatm_no_de.cmb.bkup
commondatadecisioncombatm_no_df.cmb.bkup
commondatadecisioncombatm_no_fi.cmb.bkup
commondatadecisioncombatm_no_no.cmb.bkup
commondatadecisioncombatm_pr_de.cmb.bkup
commondatadecisioncombatm_pr_fi.cmb.bkup
commondatadecisioncombatm_pr_no.cmb.bkup
commondatadecisioncombat	emplate.cmb.bkup
commondataeffectsloodfx.dat.bkup
commondataeffectsentityfx.dat.bkup
commondataeffectsexplosionfx.dat.bkup
commondataeffectsmaterialfx.dat.bkup
commondataeffectspedfx.dat.bkup
commondataeffectsvehiclefx.dat.bkup
commondataeffectsweaponfx.dat.bkup
commondatamapsambient.ipl.bkup
commondatamapscull.ipl.bkup
commondatamapsocclu.ipl.bkup
commondatamapspaths.ipl.bkup
commondatamapspaths2.ipl.bkup
commondatamapspaths3.ipl.bkup
commondatamapspaths4.ipl.bkup
commondatamapsscenarios.ipl.bkup
commondatamapsscenarios2.ipl.bkup
commondatamapsworldlights.ipl.bkup
commondatamapsworldparticles.ipl.bkup
commondatamaterialsmaterials.dat.bkup
commondatamaterialsmtl_convert.txt.bkup
commondatamaterialsprocedural.dat.bkup
commondatapathscablecar_northern.dat.bkup
commondatapathscablecar_southern.dat.bkup
commondatastreamingintro.srl.bkup
pcstream.ini.bkup
pcdatafilelist.pak.bkup
pcdatagta4pc.png.bkup
pcdatagta_cache.dat.bkup
pcdata
adiohud.dat.bkup
pcdata	imecyc.dat.bkup
pcdata	imecyclemodifiers.dat.bkup
pcdata	imecyclemodifiers2.dat.bkup
pcdata	imecyclemodifiers3.dat.bkup
pcdata	imecyclemodifiers4.dat.bkup
pcdataeffectsgtarainemitter.xml.bkup
pcdataeffectsgtarainrender.xml.bkup
pcdataeffectsgtastormemitter.xml.bkup
pcdataeffectsgtastormrender.xml.bkup
pcdataeffectsgta_core.wpfl.bkup
pcdataeffectsgta_entity.wpfl.bkup
pcdataeffectsgta_script.wpfl.bkup
pcdata
aturalmotionfred.art.bkup
pcdata
aturalmotionfred.html.bkup
pcdata
aturalmotionwilma.art.bkup
pcdata
aturalmotionwilma.html.bkup
pcdatapathsdistantlights.dat.bkup
files.txt.bkup

enjoy