Vendor field coming with default value in all transaction where Vendor occurs

Hello Experts !! ,

Need your assistance regarding one issue :

1) Vendor Field in all Transaction is coming with default value , when you click on search button , search window is not popping up .

2) Checked with Security and Basis team there no default Vendor value has been set .

3) Reinstalled SAP GUI , checked personal setting : nothing related to found

4) Checked logging ion different system , same issue .

5) Also Deleted all temp file on users system .

Vendor field coming with default value in all transaction where Vendor occurs.

Please help !!