Bu11et

hi, I'm new to this site so hope I am posting in the right section.
my wife has bought herself a tablet, she has only had it a few months and it is playing up. I cannot contact the person she bought it from, so I am hoping I can get some help on here.
the box says it is a superpad VI, and the loading screen says vinicro. the info I have found on the tablet itself is

Model Number
MID

Android Version 2.3

Kernal Version
2.6.35.7 root@zjd #39

Build Number
MID userdebug GRH55 eng.root 20111010.094312 test-keys

it is running market version 2.3.6 and I read somewhere on this site about version 3.4.4 but when I downloaded the new one and tried to install it onto the tablet it just runs through the process of installing then comes up and says app not installed.
the problems started when the tablet just went off, the battery wasn't dead, it just turned itself off, but would not turn back on so I pressed the reset button, it then turned on, but now when I turn it on, the wireless will not connect unless I press the reset button again, sometimes I have to do it a couple of times before it will connect, even then, it doesn't always stay connected for long.
the other problem is, most of the games that she has downloaded and were running fine, now when she tries to open them she gets a message saying an error has occurred and the app needs to close
I really hope someone can help
thx in advance