Kao sto kaze sam naslov imam problem sa D particijom,ne mogu je otvoriti uopste izbaci mi sledece:
 D:\ is not accessible.
The request could not be performed because of an I/O device error.

Kako da resim ovo?

probaj prvo da sekeniraš sisitem sa AV-om koji koristiš i sa Malwarebytes, da eventualno nešto nemaš.
onda uradi Check Disk (desni klik na D-->properties-->Tools-->Check Disk) ili startuj komadu "chkdsk d: /r"
(bez navodnika), pa ako ovo pomogne super, ako ne idemo dalje.

Posle skeniranja sa AV i Malwarebytes i chkdsk d: /r u command prompt sve je ostalo nepromenjeno.Ne mogu otvoriti particiju isto mi ono izbacuje.Sta dalje predlazes/te?Jako mi je bitno,sve sto mi treba je na D particiji. 

Probao si u safe mode da odes?

Ne nisam.Sta mislis da probam iz safe moda command prompt chkdsk d: /r ?

Probao i iz safe moda opet isto,nece pa nece. 

Ne, mislio sam da li se ptvara upste iz safe moda.
Jesi proveravao/testirao taj disk u skorije vreme?

Proveri prvo ovo što predlaže chelavi1. da samo pristupiš D disku iz safe moda. ako nemože onda
probaj ovo (na engleskom je, nadam se da to nije problem)

Another cause of the I/O device error is that Windows has the transfer mode for the drive or device set incorrectly. The transfer mode can be changed or corrected by the end-user if logged in to the computer in administrator mode.

Step 1 – Select the “Start” menu button and then right click the “My Computer” icon.

Step 2 – Choose the “Manage” menu option on the subsequently displayed menu. Then, click or choose the “Device Manager” menu option located beneath the “Computer Management” window.

Step 3 – Select the menu icon to expand the “IDE ATA/ATAPI” controller display. There will be one or many listings for IDE ATA/ATAPI channels available on the computer.

Step 4 – Right click the channel that corresponds to the drive that is throwing the I/O device error. If you can’t determine which IDE channel is the appropriate one for the error being thrown on your computer choose the one labeled “Secondary IDE Channel.”

Step 5 – Select the “Properties” menu option followed by opening the “Advanced Settings” menu tab.

Step 6 – Choose the “PIO Only” menu option located in the “Transfer Mode” box. This will be the device corresponding for the drive throwing the error. On most computers, the correct option will be “Device 0.” Ensure you do not change the Primary IDE Channel Device 0 when manipulating the IDE properties since this is normally the system disk. Modifying the transfer mode for this disk can result in the Windows OS failing to work properly. On computers running the Windows 7 OS, uncheck the “Enable DMA” menu option to disable DMA. This is equivalent to the “PIO Only” setting on older versions of the Windows OS.

Step 7 – Select or click the “Ok” menu button and exit the configuration applications. On the Advanced Settings tab, select PIO Only in the Transfer Mode box for the device that represents the appropriate drive. Typically, this is Device 0. Then, click OK and exit all windows.

Step 8 – Restart your computer and test the drive or device that is throwing the I/O device error.

Step 9 – If the device or drive does not work after restart, then it may not be located under the secondary IDE channel device 0. If this is the case, change device 0’s transfer mode back to DMA, and repeat the process for the Primary IDE channel device 1 and then the Secondary IDE channel device 1 if the primary does not work (remembering not to change the Primary IDE channel device 0). After each change, restart the computer.
objašnjenje je sa stranice:
http://www.tech-faq.com/io-device-error.html

pročitaj i celu stranicu ima dosta objašnjenja oko ove greške.

Ako ni ovo ne pomogne, onda predlažem da na nekom drugom kompjuteru, ako ga nemaš, zamoli nekoga kod koga možeš to da uradiš, da priključiš taj tvoj hdd i da probaš da pristupiš podacima i da ih sačuvaš, pošto ti trebaju.

Probao sam i ovo ne pomaze.Hvala na pomoci,pronacu vec valjda neko resenje.

ovaj tvoj problem je nažalost malo ozbiljniji. više upućuje na to da je hardwerski nego softwerski, mada ne mogu
to da tvrdim 100%.
što se tiče podataka oni su tu na hdd-u, jedino što ti ne možeš da pristupiš disku D.
zato je po meni najbolje da sačuvaš podatke sa tog hdd-a tako što ćeš ga skinuti i priključiti na neki drugi kompjuter,
a posle toga (možeš i pre) da proveriš taj hdd sa nekim altima tipa sentinel, i na kraju da taj hdd potuno obrišeš i instaliraš nanovo windows.
znam da je ovo mnogo ,ali to ti je moj savet za ovakvu vrstu grešaka.