Hi, my brother's year-old computer's HDD seemed to have become corrupt. Things would randomly crash, and games would sometimes say a specific file has become corrupt prompting him to reinstall. Unplugging the HDD and plugging it back in seemed to make it work for up to a day or two, but the problem would always come back, regardless of which SATA port I plugged the HDD in to (I even tried a SATA to IDE converter which had the same problems), I also changed the SATA cable and the power cable. So finally I decided to replace it with a secondary HDD from my computer which I knew worked. Now it's still having the same problem, would it be a problem with the motherboard then? Also, chkdsk seems to come up with no errors. Thanks in advance.
For easy access to memtest86+, simply download Ubuntu linux livecd (any) and burn & boot it, press ESC and select Memory Test. If you see a blue background then it is running. If you see any red text appearing in the center, your memory has errors; though it's not 100% guaranteed these are the cause of bad memory; though that is 96% the case i think.
Alright, if you get errors try to swap DRAM sticks to find out which stick it is that gives you trouble. If you don't get errors even after long testing (24hrs+ total; doesn't have to be non-stop) then another problem like a harddrive problem could be the cause of your issues. But first concentrate on memory!