Im not a computer genius, but I think I got some kind of virus and for about 10 minutes my computer got a mind of its own. I tried to watch a video on megavideo (on firefox, not IE) and then I got a message on the right hand side of the task bar telling me the firewall wasnt on (even though I didn't turn it off). I went on the windows website and downloaded one of those "fix it for me" things to switch the firewall back on.

So after that I thought (because it went so crazy) that I should do a full computer virus scan (I used AVG free version 9) and it found 4 threats, and got rid of them, so my computer was working fine again.

So I tried to open firefox again, using the icon on my desktop, and the "chose the program you want to open this file with" message came up, so i chose firefox, and it worked. But, thats the only way i can get it to work, and, every icon on my desktop, and every programme in the start menu does the same thing when i try to open them, the only one which seems to work is firefox, everything else just says that it cannot be found.

The only way to get onto programmes now is to go through a file, for example, the only way to get onto Adobe Photoshop would be to select a photo, right click and select "edit file in Adobe Photoshop" and the only way to open up AVG is to select a file, right click and select "scan with AVG Free".

I've tried to system restore, but the same thing happens, when i try and open it i just get the message telling me that it cannot be found.

Iv'e also tried to re-install firefox, but when I try and open the installer, it does the same thing again (the message I'm talking about is this one http://img130.imageshack.us/img130/456/error1z.jpg ).

Can anyone please tell me whats wrong with it ? Or how I can fix it, or how I can open system restore using the "Start>Run" way?

Sounds like the file location of those applications cant be found; have you perhaps installed them on a removable drive... if so they may be the cause. Sometimes when you remove and then re-insert the drive the location like 'F:' this can then be substituted with a different one.... Try right clicking on the Icon and checking if the file path is correct.
You could always try a 'Repair or 'Full install' of your operating system.
If you think that the issue is due to some Virus; then perhaps try different applications of Anti Virus or Malware; you could try Spy-bot Search & Destroy?

You could try accessing 'System Restore' using Command Prompt:
open a Command Prompt window. To do this, follow these steps:
Click Start, click Run, type CMD in the Open box, and then press Enter.
Type Net Start at the command prompt to make sure that the System Restore Service is up and is running.

If the System Restore Service is not listed, type net start "System Restore Service", and then press Enter.

other than this I am really not sure....sorry

System restore is NOT a good idea especially since you have all ready removed some infections. Chances are the restore points could be infected. Leave it alone, don't turn it off, don't use it. That can be dealt with later.
Do the following:
Please download Malwarebytes' Anti-Malware (MBA-M) to your Desktop.

* DoubleClick mbam-setup.exe and follow the prompts to install MBA-M.
* Be sure a checkmark is placed next to Update Malwarebytes' Anti-Malware and Launch Malwarebytes' Anti-Malware, then click Finish.
* If an update is found, it will download and install the latest version.
* Once the program has loaded, select Perform full scan, then click Scan.
* When the scan is complete, click OK, then Show Results to view the results.
* Be sure that everything is checked, and click Remove Selected.
* When MBA-M finishes, Notepad will open with the log. Please save it where you can find it easily. The log can also be opened by going to Start > All Programs > Malwarebytes' Anti-Malware > Logs > log-date.txt.

REBOOT after running MBA-M!

Post back here and copy/paste that MBA-M log here. It would also help to know the exact names and locations of the infected files found by AVG.
Judy

I actually found out what the problem was and forgot to post it on here, it was a really bad virus, and i used Malwarebytes anti-malware which got rid of it. I did the scan in safe mode, then rebooted and the problem has gone!

Since you did the MBA-M in safe mode then you need to update it again and then run the full scan again in Normal Mode. MBA-M does NOT scan all files in safe mode as it is really to be run in Normal Mode. In an emergency such as this one it can be done in safe mode and will remove but definitely should be done again in Normal Mode so you are absolutely certain that all files will be scanned and any remainder removed.

My problem was described exactly above. I cannot open programs or download programs to fix the problem. It always says: Choose the program you want to open this file. so I cannot run the fixes. HELP

My problem was described exactly above. I cannot open programs or download programs to fix the problem. It always says: Choose the program you want to open this file. so I cannot run the fixes. HELP

This thread is over one year old and belongs to another person. You must create your own thread, stating all problems and including all requested logs from the tools you must run in advance which can be found in our Read Me First Sticky. Only after that can anyone provide you with assistance.
Follow the steps given here and create your own thread:
http://www.daniweb.com/hardware-and-software/microsoft-windows/viruses-spyware-and-other-nasties/threads/134865

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