@elfisho --
jucheck.exe is the name of the program that checks for Java updates. Unfortunately, however, malware can also use the same name.
On my Win 7 Pro x64 system, I have only one instance of jucheck.exe, and it is in
C:\Program Files (x86)\Common Files\Java\Java Update\jucheck.exe
It's a different size than yours -- 499 KB (511,872 bytes) -- and probably a newer version, if you haven't let Java update in a while (mine is version 2.1.60.19; you can right-click on your file, select Properties and then the "Details" tab).
You've copied an old response from 2011, so I don't know if you have scanned the files you found. If you have scanned them with an up to date antivirus, then you're probably OK.
If you're concerned, submit the file(s) to https://www.virustotal.com/ where they will be checked automatically (in real time) by a large collection of antimalware tools.
If I were you, I'd do the following:
- Go to Control Panel > Programs and Features and uninstall anything that starts with "Java" (the current version is Java 7 Update 60)
- Go to http://java.com/en/download/uninstallapplet.jsp and click the "Agree and Continue" button
- If any older versions of Java are found, they will be uninstalled. Then download the installer stub for the current version.
- Before you install the current version, check in the locations where you previously had found jucheck.exe and if any of the files are still there, delete them.
- Run the file you downloaded; this will download the full installer and then start the installation process. Be sure to UNCHECK the boxes that will otherwise install the Ask Toolbar.