Excel files file1.xlsx file2.xlsx not found

[Sachit]

I have a computer with Windows Vista that i was happy with and it never gave me a problem before. Now there is a problem with my Excel 2007 files. Whenever i try to open a file with .xlsx extension [excel files] i would get error file1.xlsx not found. Then there would be a series of files with excel extension which will return the same error even i've not even tried to open them. This problem started just 2 days ago and i'm unable to find any solution myself... Please help guys! My overall computer has become slow after this error started appearing...

[Mozilla]

Might be your computer is infected by some trojan horse or similar worm. Which antivirus do you use? Is it fully updated? If not please update it and try to scan your computer for viruses or any kind of infections. This may be one cause of the error that you are receiving... If proper care is not taken, it may spread and a system crash may occur... All the best!

[Sachit]

I don't have any antivirus because i don't have that computer connected to the internet, i have kept it isolated from any and all network too and dedicated it only for my work. For transfering files i use a CD-R and burn it as even pen drives get infected by virus and i can't risk my computer. Also my data needs are too less so i need not worry about it much. The problem i can think is once i was working on excel and there was a power cut... Can the problem be due to the power loss? Help!!

[ThoMas321]

Try to unregister and register excel again. Try this out :
Go to start menu and click on run and then type :

excel.exe /unregserver

Now reboot your computer and again in the run type :

excel.exe /regserver

This might be able to solve your problem. And if it doesn't, do post back...