wrong power plug corrupted files

Hi. My problem is I am running windows 7 on a laptop given to me by a friend. She also gave me a docking station that goes to it. My boyfriend accidently plugged in the laptop with the cord that goes to the docking station, and it was like that for about a week. One day i got a error message, i can't remember exactly what it said, but it did say that some files were corrupted and asked to delete them, i said ok. It ran kind of buggy for about a week, then smoothed out and was running alright. (It also wouldn't run the repair disc i made for it. It booted with it, but wouldn't run the repair program).

Then yesterday i tried to install a driver to connect to my gtc incredible phone by bluetooth. It installed almost all of the bundle except for one file (the first one) called "MSXML 4.0 SP3". I am wondering what i should do, of course i'd like to have the bluetooth working, but more so, i am afraid something is wrong with the computer. Is there anything that could diagnose the errors and fix them? We really can't afford to take it to a repair shop.

Any help you could give us will be much appreciated.

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Professional, Service Pack 1, 64 bit
Processor: Intel(R) Core(TM)2 Duo CPU P9600 @ 2.53GHz, Intel64 Family 6 Model 23 Stepping 10
Processor Count: 2
RAM: 3992 Mb
Graphics Card: Mobile Intel(R) 4 Series Express Chipset Family, 1772 Mb
Hard Drives: C: Total - 226772 MB, Free - 153973 MB; Q: Total - 10500 MB, Free - 4036 MB;
Motherboard: LENOVO, 2801CTO
Antivirus: AVG AntiVirus Free Edition 2013, Updated and Enabled