I have got a desktop system, I had a intel celeron processor, 80 GB of internal hard drive and 256 of RAM installed in my system, I know you will laugh looking at such configuration being used in today's generation, but do not worry I made a lot of changes then . I mentioned it because I have not changed my CPU cabinet yet, then I bought intel core i5 processor, upgraded and a the Disk drive as well and increased the capacity upto 500 GB of hard disk, I installed 2GB of RAM by mounting two RAM sticks on my ASUS motherboard which can be collectively be used as 2 GB of RAM. I used to use Windows xp home edition in my old configuration, after upgrading I installed Windows Vista in the place of windows xp. I did all this things 8 months back, the due to performance issues I got fed up of Windows Vista and I replaced it with Windows 7 of 64 bit version. But I did not know it will too come up with issues straight away , all the executable files which are in the.exe format are by default opening in the Adobe reader. I can do nothing but just watch those files open in Adobe reader , if anybody knows how to resolve it as I cannot run a lot of programs due to this issue and it is driving me crazy. Please give quichk and effective solution for this error.